Human intestinal epithelial cell-derived interleukin (IL)-18, along with IL-2, IL-7 and IL-15, is a potent synergistic factor for the proliferation of intraepithelial lymphocytes

Intestinal epithelial cell (IEC)-derived cytokines, such as stem cell factor (SCF), interleukin (IL)-7 and IL-15 are known to be required for the development of intestinal intraepithelial lymphocytes (IELs). A newly described cytokine, IL-18, has also been shown to be produced by intestinal epithelial cells. To demonstrate the functional effects of IL-18 on human IELs, we assessed IL-18/IL-18 receptor expression in IEC/IEL and proliferation following stimulation of intestinal IELs by IL-18. IL-18 transcripts were detected both in freshly isolated human colonic epithelial cells and in various colonic epithelial cell lines. IL-18 protein was also detected by ELISA and flow cytometric analysis using antihuman IL-18-specific monoclonal antibody (MoAb). Furthermore, IELs constitutively expressed the IL-18 receptor in addition to the IL-2 and IL-7 receptors. More importantly, IL-18 augmented significant proliferative responses of IEL in combination with IL-2, IL-7 and IL-15 both in the presence and in absence of anti-CD3 MoAb. These results suggest that IL-18 might play a crucial role in the proliferation and maintenance of intestinal IELs.

PRQFVamide, a novel pentapeptide identified from the CNS and gut of Aplysia

We have purified a novel pentapeptide from the Aplysia nervous system using bioassay on gut contractions. The structure of the peptide is Pro-Arg-Gln-Phe-Val-amide (PRQFVa). The precursor for PRQFVa was found to code for 33 copies of PRQFVamide and four related pentapeptides. Peaks corresponding to the predicted masses of all five pentapeptides were detected in Aplysia neurons by matrix-assisted laser desorption/ionization time-of-flight mass spectrometry. Northern analysis revealed that expression of the precursor is abundant in the abdominal ganglion, much less in the pedal and cerebral ganglia, and rarely seen in the buccal and pleural ganglia. PRQFVa-positive neurons, mapped by immunohistochemistry and in situ hybridization, were present in all the central ganglia. PRQFVa immunopositive processes were observed in the gut, particularly in association with the vasculature. Some arteries and other highly vascularized tissues, such as the gill and the kidney, also contain numerous PRQFVa immunopositive processes. Application of synthetic PRQFVa suppresses not only contractions of the gut but also contractions of vasculature. PRQFVa is expressed in some of the neurons within the feeding circuitry and application of synthetic PRQFVa was found to decrease the excitability of some (B4/5 and B31/32) but not all (B8) neurons of the buccal feeding circuit. Our findings suggest that PRQFVa may act as a modulator within the feeding system as well as in other systems of Aplysia.

The enterins: a novel family of neuropeptides isolated from the enteric nervous system and CNS of Aplysia

To identify neuropeptides that have a broad spectrum of actions on the feeding system of Aplysia, we searched for bioactive peptides that are present in both the gut and the CNS. We identified a family of structurally related nonapeptides and decapeptides (enterins) that are present in the gut and CNS of Aplysia, and most of which share the HSFVamide sequence at the C terminus. The structure of the enterin precursor deduced from cDNA cloning predicts 35 copies of 20 different enterins. Northern analysis, in situ hybridization, and immunocytochemistry show that the enterins are abundantly present in the CNS and the gut of Aplysia. Using matrix-assisted laser desorption/ionization time-of-flight mass spectrometry we characterized the enterin-precursor processing, demonstrated that all of the precursor-predicted enterins are present, and determined post-translational modifications of various enterins. Enterin-positive neuronal somata and processes were found in the gut, and enterins inhibited contractions of the gut. In the CNS, the cerebral and buccal ganglia, which control feeding, contained the enterins. Enterin was also present in the nerve that connects these two ganglia. Enterins reduced the firing of interneurons B4/5 during feeding motor programs. Such enterin-induced reduction of firing also occurred when excitability of B4/5 was tested directly. Because reduction of B4/5 activity corresponds to a switch from egestive to ingestive behaviors, enterin may contribute to such program switching. Furthermore, because enterins are present throughout the nervous system, they may also play a regulatory role in nonfeeding behaviors of Aplysia.

Interleukin 18 is a potent proliferative factor for intestinal mucosal lymphocytes in Crohn's disease

BACKGROUND & AIMS

Crohn's disease (CD) is characterized by a marked accumulation of activated Th1 type CD4(+) T cells and macrophages in inflamed intestinal mucosa. Interleukin (IL)-18 is a recently described cytokine that mainly exists in activated macrophages and shares biological activities with IL-12 in driving the development of Th1 type CD4(+) T cells by inducing interferon gamma. To clarify the role of IL-18 in intestinal inflammation in CD, we assessed the functional role of IL-18 in regulating intestinal mucosal lymphocytes.

METHODS

Serum IL-18 concentration was measured by enzyme-linked immunosorbent assay. Expression of IL-18 and IL-18 receptor in human intestinal mucosa was determined using immunohistochemistry and flow cytometry. The functional activity of IL-18 was assessed by the use of recombinant IL-18 to stimulate both the growth of intestinal mucosal lymphocytes and IL-2 receptor induction activity.

RESULTS

The serum IL-18 concentration was significantly higher in patients with CD than normal controls. In the inflamed colonic mucosa of CD, many IL-18(+)CD68(+) macrophages had infiltrated the lamina propria. Intestinal mucosal lymphocytes from CD expressed functional IL-18 receptors. Recombinant IL-18 induced significant proliferative responses in freshly isolated mucosal lymphocytes from CD patients, but not from normal controls. IL-18 up-regulated IL-2 receptor expression in mucosal lymphocytes from patients with CD, but not from normal controls.

CONCLUSIONS

These findings suggest that infiltrated macrophages in the inflamed intestinal mucosa in CD produce IL-18, and that macrophage-derived IL-18 may serve as a potent regulatory factor for intestinal mucosal lymphocytes, thereby contributing to chronic intestinal inflammation in CD.

Development of novel simian immunodeficiency virus vectors carrying a dual gene expression system

The development of highly efficient and safe gene transfer methods suitable for clinical use is required for human gene therapies. We have developed a novel lentiviral vector system, based on the nonpathogenic simian immunodeficiency virus from African green monkeys (SIVagm), that carries a unique dual gene expression system. This system utilizes the lentivirus Rev responsive element (RRE). Self-inactivating vectors were also developed by deleting a U3 region in the 3' long terminal repeat (3' LTR) of the virus. When pseudotyped with a vesicular stomatitis virus envelope glycoprotein G (VSV-G), the SIVagm-based vectors could transduce both growth-arrested human cells and terminally differentiated neuronal cell lines. Using these vectors, two reporter genes could be expressed simultaneously at equal levels, and expression levels of both genes could be altered by modifying the length of the RRE sequence. These SIVagm-based vectors might offer safety advantages over other lentivirus-based vectors. Furthermore, the novel dual gene expression system described here could increase the usefulness and value of both viral and nonviral vectors in gene therapy.

The Aplysia mytilus inhibitory peptide-related peptides: identification, cloning, processing, distribution, and action

Neuropeptides are a ubiquitous class of signaling molecules. In our attempt to understand the generation of feeding behavior in Aplysia, we have sought to identify and fully characterize the neuropeptides operating in this system. Preliminary evidence indicated that Mytilus inhibitory peptide (MIP)-like peptides are present and operating in the circuitry that generates feeding in Aplysia. MIPs were originally isolated from the bivalve mollusc Mytilus edulis, and related peptides have been identified in other invertebrate species, but no precursor has been identified. In this study, we describe the isolation and characterization of novel Aplysia MIP-related peptides (AMRPs) and their precursor. Several AMRPs appear to have some structural and functional features similar to vertebrate opioid peptides. We use matrix-assisted laser desorption/ionization time-of-flight mass spectrometry to confirm that all 14 AMRPs predicted by the precursor are processed in isolated neurons. Northern analysis, whole-mount in situ hybridization, and immunohistochemistry are used to map the abundant expression of these peptides in the CNS and peripheral tissues such as the digestive tract, vasculature, and the reproductive organs. Physiological studies demonstrate that the rank order of the inhibitory actions of these peptides is different for three target muscles. These results underscore the importance of using a multidisciplinary approach to identifying and characterizing the actions of neuropeptides in an effort to gain understanding of their role in systems of interest. The widespread distribution of the AMRPs indicates that they may be operating in many different systems of Aplysia.

Selective expression of beta 7 integrin on lymphocytes undergoing apoptosis in lymphoid tissues

It has been previously shown that the beta 7 chain of integrin forms heterodimers with the alpha 4 or alpha E chain, which plays essential roles in lymphocyte homing to mucosal lymphoid tissues. The aim of this study was to re-evaluate the possible role of the beta 7 integrin other than lymphocyte homing. We prepared spleen and lymph node lymphocytes from biopsied specimens from macaque monkeys and examined for the reactivity with a monoclonal antibody specific for the beta 7 chain. As a result, a minor population of the lymphocytes with a smaller size, which were in the early stage of apoptosis, was found to express a higher level of the beta 7 integrin than a majority of the lymphocytes with a normal size. Interestingly, the apoptotic lymphocytes expressed neither alpha 4 nor alpha E chains, suggesting that the beta 7 chain on these cells may be associated with an undefined alpha chain. These findings indicate that in the lymphoid tissues the shrunken lymphocytes undergoing apoptosis selectively express a unique beta 7 integrin.

[Influence of fluid replacement on serum magnesium concentration and proper magnesium supplementation during general anesthesia]

We have studied the influence of fluid replacement on serum magnesium (Mg2+) concentrations, and studied proper Mg2+ supplementation during general anesthesia. Thirty eight patients undergoing elective surgery randomly received: Mg(2+)-free acetated Ringer solution (Group I, n = 15), acetated Ringer solution containing 0.5 mmol.l-1 of Mg2+ (Group II, n = 6), 1.0 mmol.l-1 of Mg2+ (Group III, n = 7), 2.0 mmol.l-1 of Mg2+ (Group IV, n = 6), or 4.0 mmol.l-1 of Mg2+ (Group V, n = 4). Measurements were made on serum and urine Mg2+ concentrations during anesthesia. In Group I, the serum Mg2+ concentrations decreased in correspondence with the water balance. It is suggested that dilution due to the fluid replacement induced the reduction in serum Mg2+ concentrations since the observed urine Mg2+ concentrations were negligible. In Group II-V, the reduction in serum Mg2+ concentrations was inhibited by Mg2+ supplementation, and the serum Mg2+ concentrations remained unchanged in Group IV. We conclude the Mg2+ supplementation is required during anesthesia when a large amount of fluid is infused.

Uric acid excretion increases during propofol anesthesia

We compared the effect of propofol with that of sevoflurane anesthesia on uric acid (UA) excretion in ASA physical status I and II patients with normal renal function. A propofol group (n = 11) received propofol-nitrous oxide-fentanyl after induction of anesthesia by propofol, while a sevoflurane group (n = 12) received sevoflurane-nitrous oxide-fentanyl after induction of anesthesia by thiamylal. UA, creatinine (Cr), and urea nitrogen concentrations in serum and urine were measured before induction of anesthesia, 1, 2, and 3 h after induction, and on Postoperative Day 1. N-acetyl-beta-D-glucosaminidase, beta2-microglobulin concentrations, and pH in urine were also examined. Plasma clearance of UA (CUA) and Cr (CCr) were calculated. The hourly concentration and excretion of urine UA were significantly higher than those of the sevoflurane group (P < 0.01). Significant correlations were noted between the hourly urine volume and UA concentration (r = 0.58, P < 0.01 for the propofol group; r = 0.51, P < 0.01 for the sevoflurane group). The CUA of the propofol group was significantly higher than that of the sevoflurane group (22.9 +/- 10.6 vs 5.9 +/- 3.4 mL/min, mean +/- SD, P < 0.05). There were no significant differences in other renal variables between the two groups. The present study demonstrated that the UA excretion increased during propofol anesthesia, while it remained stable during sevoflurane anesthesia.

[The pharmacokinetics of D-lactate, L-lactate and acetate in humans]

In this study, the pharmacokinetics of D-lactate, L-lactate and acetate were investigated in 36 adult surgical patients. After induction of general anaesthesia, the subjects received intravenous injection of either 5 mmoles of D-lactate and 5 mmoles of L-lactate simultaneously (Group DL), 10 mmoles of L-lactate (Group L), or 10 mmoles of acetate (Group A). Serial arterial blood samples were obtained before the injection, and 3, 5, 7, 9 and 11 minutes after the infusion of each preparation. Plasma concentrations of D-lactate, L-lactate and acetate were measured by high performance liquid chromatography, enzymatic analysis and spectrophotometry. The pharmacokinetic parameters; distribution volume (Vd) and half-life (t1/2) were calculated with a one-compartment model from the incremental plasma concentration decay curve after administration. In Group DL, there were no differences between D-lactate and L-lactate in Vd and t1/2. Also, between L-lactate in Group DL and that in Group L, there were no differences in Vd and t1/2. The Vd and T1/2 of acetate, however, were smaller than those of L-lactate in Group L. We conclude that the pharmacokinetics of D-lactate is similar to those of L-lactate, and that acetate may be metabolized more rapidly than L-lactate.

[Effect of mesalazine, an agent for the treatment of idiopathic inflammatory bowel disease, on reactive oxygen metabolites and LTB4 formation]

Mesalazine microgranules (Pentasa) were developed as a drug for idiopathic inflammatory bowel diseases such as ulcerative colitis and Crohn's disease. In this study, we examined the effect of mesalazine on radical scavenging, lipid peroxidation and the formation of LTB4. Mesalazine reduced the free radical 1,1-diphenyl-2-picrylhydrazyl with an IC50 value of 9.5 microM. It scavenged hydrogen peroxide and hypochlorite (IC50: 0.7 microM and 37.0 microM, respectively), but had no effect on superoxide. Lipid peroxidation in rat liver microsomes was inhibited by mesalazine (IC50: 12.6 microM). Mesalazine significantly inhibited (P < 0.01) gastric mucosal lipid peroxidation induced by ischemia and reperfusion in rats at a dose of 50 mg/kg, p.o. Mesalazine also inhibited the formation of LTB4 in rat peritoneal neutrophils (IC50: 44.9 microM). N-Acetyl-mesalazine, the metabolite of mesalazine, had no effect on radical scavenging and lipid peroxidation. Only a high concentration (1 mM) of the metabolite inhibited the formation of LTB4. These studies suggest that mesalazine inhibits cell injury in the inflamed mucosa by scavenging reactive oxygen metabolites and prevents the invasion of neutrophils by inhibition of LTB4 formation.

[Effect of mesalazine microgranules on experimental colitis]

Mesalazine microgranules are an ethylcellulose-coated formulation from which mesalazine is released throughout the intestinal tract and are expected to be effective for idiopathic inflammatory bowel disease, ulcerative colitis and Crohn's disease. Mesalazine microgranules were administered orally to investigate the distribution of mesalazine throughout the intestinal tract in rats. Mesalazine microgranules distributed sufficient amounts of mesalazine and its metabolite, N-acetyl-mesalazine, to the intestinal tissues, while pure mesalazine delivered lower amounts of both. In acetic acid-induced colitis in rats, mesalazine microgranules administered orally reduced the damage score significantly (P < 0.05) at a dose of 50 mg/kg as assessed by macroscopic observation and at 100 mg/kg as assessed by histological evaluation. The number of ulcers in carrageenan-induced colitis in guinea pigs was inhibited at doses of 50, 100, 200 mg/kg, p.o. The colonic wet weight of rats in 2,4,6-trinitrobenzenesulfonic acid (TNB)-induced colitis was reduced significantly (P < 0.05) at a dose of 50 mg/kg, p.o. Mesalazine microgranules showed the ability to distribute mesalazine efficiently throughout the intestinal tract and showed effectiveness against acetic acid-, carrageenan- and TNB-induced colitis. These studies strongly suggest that mesalazine microgranules are effective for idiopathic inflammatory bowel disease.

Comparative study of intravenous administration of Ringer’s lactate, Ringer’s acetate and 5% glucose containing these Ringer’s solutions in human being

The effects of the administration of Ringer's lactate (L) and Ringer's acetate (A) solution on blood biochemistry in human subjects operated for tympanoplasty under general anesthesia were investigated. And the feasibilities of the clinical use of Ringer's lactate (LD) and Ringer's acetate (AD) solution containing 5% glucose were also assessed. In all cases the rate of infusion was 500 ml for initial 20 min, and then 5 ml.hr(-1).kg(-1) B.W. for 3 hr and 10 min. There were significant increases in blood L- and D-lactate, pyruvate, and L-lactate/pyruvate ratio in L group. A significant increase in blood acetate but not lactate was found in A group. These metabolic changes were minimal and considered as clinically not significant. The urinary excretion of lactate, pyruvate, acetate and glucose were also negligible. In both LD and AD group, the higher blood concentrations of lactate, pyruvate, acetate and glucose were found than in L and A group. Urinary excretions of these metabolites were much higher in LD and AD group than in L and A group. So glucose containing Ringer's lactate or acetate solutions should be administered in appropriate amounts and rate not to induce clinically significant metabolic alterations.

Antiulcer activities of glycyrrhetinic acid derivatives in experimental gastric lesion models

Glycyrrhetinic acid (Ia) and eighteen related derivatives were examined for antiulcer activity using stress-induced gastric lesions (restraint plus water immersion at 25 degrees C) in mice and rats as screening tests. Among the compounds tested, dihemiphthalate derivatives of 18 alpha- or 18 beta-olean-12-ene-3 beta,30-diol (IV, IIId), 18 beta-olean-9(11)12-diene-3 beta,30-diol (VIc), and olean-11,13(18)-diene-3 beta,30-diol (VIIc) showed potent inhibition of gastric lesion formation at a dose of 12 or 25 mg/kg (p.o.); carbenoxolone sodium (Ib) significantly suppressed the lesion formation at a dose of 500 mg/kg (p.o.). Further evaluation of the antiulcer activity was carried out mainly for compound IIId. Compound IIId (p.o.) prevented the formation of indomethacin-induced or 0.6 N HCl-induced gastric lesions; the latter antiulcer effect was noted even in the combined treatment with indomethacin, suggesting that the effect occurs independently of endogenous prostaglandins. In contrast, compound IIId had no preventive effect against Shay rat ulcer when intragastrically (i.g.) administered; further, no antisecretory effect was seen by i.g. application in pylorus-ligated rats. Administration of compound IIId for 2 weeks accelerated the healing rate of acetic acid-induced gastric ulcer in rats. No significant change in urine excretion was observed after its consecutive administration for 3 d. These results suggest that dihemiphthalate derivatives (IIId, IV, VIc, VIIc) may produce a strong antiulcer activity, probably by strengthening some gastric mucosal defensive mechanism.