New immunosuppression with monoclonal antibody to intracellular adhesion molecule 1 (ICAM-1) in rat organ transplantation

Inbred, male Lewis rats underwent heterotopic heart allografting from F344 donor rats, or streptozocin (STZ)-induced diabetic Lewis rats underwent pancreas allografting with bladder drainage from F344 or ACI donor rats. A monoclonal antibody (MoAb) to intracellular adhesion molecule 1 (ICAM-1) was given i. p. (1.0 mg/kg) for 10 days, and its immunosuppressive potency was evaluated. The mean survival time (MST) of the heart allografts was significantly prolonged in the MoAb-treated group. Both exocrine and endocrine MST of pancreas allografts were also prolonged by MoAb administration across the minor and major histocompatibility barriers. However, complete graft tolerance was not induced. Our study demonstrated that the MoAb to ICAM-1 alone can delay the allograft rejection in rat organ transplantation.

Expression and role of mannose receptor/terminal high-mannose type oligosaccharide on osteoclast precursors during osteoclast formation

Osteoclasts are formed from hematopoietic precursors via cell-cell fusion. We have previously reported that mannose residues are expressed on the outer membranes of monocytes during osteoclast differentiation. In the present study, we have attempted to demonstrate the pattern of expression levels of terminal high-mannose type oligosaccharide and to show that the mannose receptor is expressed on osteoclast precursor cells. Osteoclasts were formed using three different systems, namely mouse bone marrow cell culture, co-culture of mouse spleen cells with stromal cells, and RAW264.7 cell cultures. During osteoclast differentiation, the expression of terminal high-mannose type oligosaccharide gradually increased and then peaked at the stage of fusion in all three systems. Expression of the mannose receptor gradually increased during osteoclast differentiation in bone marrow cells and the co-culture system. In contrast, that in RAW264.7 cells had already been detected in the absence of the soluble receptor activator of NF-kappaB ligand and did not change during osteoclast differentiation. To ascertain whether expression of high-mannose type oligosaccharide is involved in tartrate-resistant acid phosphatase (TRAP)-positive multinucleated cell (MNC) formation, glycosidase inhibitors were used on RAW264.7 cell culture. Castanospermine, an inhibitor of glucosidase I, inhibited the TRAP-positive MNCs, and deoxymannojirimycin, an inhibitor of alpha-mannosidase I, increased the TRAP-positive MNC formation. These results indicate that the binding of terminal high-mannose and mannose receptor is important for the process of cellular fusion in osteoclast formation.

Preventive effect of sulphated colominic acid on P-selectin-dependent infiltration of macrophages in experimentally induced crescentic glomerulonephritis

Leucocytes infiltrate into renal tissue and are involved in the pathogenesis of crescentic glomerulonephritis. The initial event in the process of leucocyte infiltration is characterized by selectin-mediated leucocyte rolling on endothelial surface. Role of selectins in pathogenesis of glomerulonephritis has still been controversial. Sulphated glycolipids and sulphated polysaccharides interfere with the binding of P- and L-selectin with carbohydrate ligands on endothelial cells or on leucocytes. Here we evaluated the role of selectins and the preventive effects of sulphated colominic acid (SCA), a synthetic sulphated polysaccharide, on experimental crescentic glomerulonephritis in Wistar-Kyoto (WKY) rats. Crescentic glomerulonephritis was induced by injection of nephrotoxic serum (NTS) in WKY rats. Rats subsequently received intraperitoneal injection of saline, neutralizing or non-neutralizing monoclonal antibody (mAb) to rat P-selectin and L-selectin, SCA (5 or 10mg/kg/day) or nonsulphated colominic acid (CA) (10mg/kg/day) for 2 weeks. Localization of P-, E-selectin, ligands for L-selectin and intraglomerular leucocytes was examined by immunohistochemistry. Gene expression of platelet-derived growth factor (PDGF) B chain in glomeruli was quantified using real-time RT-PCR. P-selectin was highly expressed on glomerular endothelial cells after injection of NTS, whereas E-selectin and L-selectin ligands were not detected. Anti-P-selectin mAb, but not anti-L-selectin mAb, significantly reduced glomerular infiltration of macrophages, crescent formation, and proteinuria. SCA also reduced proteinuria, macrophage infiltration, and crescent formation in a dose-dependent manner. Furthermore, SCA suppressed gene expression of PDGF B chain in glomeruli. Our results indicate that P-selectin partially mediates glomerular infiltration of macrophage in experimental crescentic glomerulonephritis. Moreover, SCA may inhibit intraglomerular infiltration of macrophages by interfering with P-selectin-dependent adhesion pathway, and progression of experimental crescentic glomerulonephritis.

Locally expressed CTLA4-Ig in a pancreatic beta-cell line suppresses accelerated graft rejection response induced by donor-specific transfusion

AIMS/HYPOTHESIS

This study examined whether locally expressed CTLA4-Ig can suppress the accelerated islet allograft rejection that is induced by donor-specific transfusion.

METHODS

CTLA4-Ig-transfected or parental MIN6 cells were transplanted subcutaneously into the right flank of streptozotocin-induced diabetic C3H/Hej mice with or without donor-specific transfusion. For donor-specific transfusion, spleen cells from C57BL/6 mice were injected i.v. at the time of transplantation. In other experiments, CTLA4-Ig-transfected and parental MIN6 cells were transplanted separately into each flank, together with donor-specific transfusion. Rejection was defined as a blood glucose concentration of more than 300 mg/dl in two consecutive measurements, and graft survival was confirmed by hyperglycaemia after the grafts were removed. The effect of an anti-CTLA4 antibody on the survival of CTLA4-Ig-transfected MIN6 cells was also examined.

RESULTS

In 7 of 12 donor-specific transfusion sensitised mice, CTLA4-Ig-transfected MIN6 cells remained viable 20 days after grafting, whereas all parental MIN6 cells ( n = 10) were rejected promptly, within 14 days. The prolonged allograft survival was observed even in the absence of detectable levels of serum CTLA4-Ig, while the surviving allografts continued to produce CTLA4-Ig in situ. This protection was abrogated by an anti-CTLA4 antibody, but not by a control antibody. Furthermore, six animals that maintained normoglycaemia after the separate transplantation of parental and CTLA4-Ig-transfected MIN6 cells into each flank all showed abrupt hyperglycaemia after the CTLA4-Ig/MIN6 graft was removed, suggesting that this protection operated locally.

CONCLUSION/INTERPRETATION

A beta-cell line genetically engineered to secrete CTLA4-Ig can protect a graft locally from the alloimmune response induced by donor-specific transfusion.

A case of rupture of the internal jugular vein caused by postoperative infection of functional neck dissection

A 68-year old diabetic man with gingival cancer of the lower jaw underwent resection of the mandible and functional neck dissection. Swabs of a postoperative wound infection revealed methicillin-resistant Staphylococcus aureus (MRSA). The wound was irrigated, and antibiotics administered. The pathogens isolated were sensitive to the antibiotics used, but the infection failed to respond to treatment. Bleeding ensued on the 14th postoperative day (#14POD), when the wound was opened to reveal thrombosis and rupture of the right internal jugular vein. The patient's condition improved after ligation and surgical debridement of the right internal jugular vein. Our experience underlines the importance of early radiological investigation for possible thrombus formation in the internal jugular vein in cases of postoperative wound infection follows functional neck dissection with conservation of the internal jugular vein. It is also important to actively treat this condition surgically, including ligation of internal jugular vein for suppressing inflammation.

The failure of oral tolerance induction is functionally coupled to the absence of T cells in Peyer's patches under germfree conditions

Although intestinal bacterial flora has been thought to play a role in the induction of oral tolerance, the mechanism has yet to be elucidated. We therefore examined the bacterial flora-dependent acquisition of susceptibility to oral tolerance induction using a gnotobiotic murine model. Germ-free (GF) mice exhibited a significant shortage of T cells in the PPs in comparison to SPF mice. A recovery in the number of such T cells was accomplished in the gnotobiotic mice associated with Bifidobacterium infantis or Escherichia coli but not in the gnotobiotic mice with Clostridium perfringens or Staphylococcus aureus. To examine the susceptibility to oral tolerance induction, these mice were orally given ovalbumin (OVA) as a tolerogen and then injected i.p. with the Ag. The Ag-specific IgG1 in the serum remained at a low level in both SPF and those gnotobiotic mice groups containing a sufficient number of T cells in the PPs. However, no such unresponsiveness in the Ab response was observed in GF or the other gnotobiotic mice groups containing only a few T cells in the tissues. Adoptive cell transfer analysis clearly showed that a sufficient number of T cells in the PPs is required for the induction of oral tolerance. Furthermore, the reduced expression of SLC (secondary lymphoid-tissue chemokine), which is responsible for T-cell migration to lymphoid organs, was observed in the PPs of GF mice, resulting in a shortage of T cells in the tissues. However, the reduced expression of SLC was restored even in the GF mice after conventionalization, thus suggesting that the failure of oral tolerance induction is functionally coupled to the innate absence of T cells under the GF condition.

Involvement of mucosal addressin cell adhesion molecule-1 (MAdCAM-1) in the pathogenesis of granulomatous colitis in rats

Although increased expression of mucosal addressin cell adhesion molecule-1 (MAdCAM-1) has been demonstrated in inflammatory sites of various diseases, its role in colitis remains unknown. In this study, we examined whether MAdCAM-1 is involved in the pathogenesis of granulomatous colitis induced by peptidoglycan-polysaccharide (PG-PS). Experimental colitis was induced by intramural injection of PG-PS to rat colon. After 3 weeks the colon was removed and the mucosal inflammation was assessed. The area of MAdCAM-1-positive venules and the subsets of infiltrating cells were determined in colonic mucosa by immunohistochemistry. In another experiment, monoclonal antibody against MAdCAM-1 was administered intraperitoneally to examine its attenuating effect on colitis. The intramural injection of PG-PS induced significant colonic inflammation with granuloma formation. The submucosa was drastically thickened with the infiltration of CD4 positive lymphocytes and ED-1 positive macrophages. Intense MAdCAM-1 expression was observed on endothelium of the submucosal venules in inflamed mucosa. Administration of anti-MAdCAM-1 antibody significantly attenuated the PG-PS-induced colonic damage and cell infiltration. Enhanced expression of MAdCAM-1 was demonstrated in venular endothelium of the inflamed colon in PG-PS-induced colitis. The attenuating effect of anti-MAdCAM-1 suggests the importance of the MAdCAM-1-dependent process in the formation of chronic granulomatous colitis.

Hepatocyte growth factor/scatter factor is implicated in the mode of stromal invasion of uterine squamous cervical cancer

OBJECTIVE

The purpose of this study was to examine the relationship of hepatocyte growth factor/scatter factor (HGF/SF) to cell motility and invasion in uterine cervical cancer.

METHODS

We examined the expression of HGF/SF and its receptor, c-met, in cervical cancer cell lines SKG-IIIa (squamous cell carcinoma) and Hela-S3 (adenocarcinoma) and in stromal cells of the cervical cancer tissue by reverse transcription-polymerase chain reaction. We studied the effect of HGF/SF on invasiveness of SKG-IIIa and Hela-S3 in an invasion model of the modified Boyden chamber method and by electron microscopy. SKG-IIIa cells were also seeded on the thick Matrigel-coated layer to evaluate the invasion patterns in three-dimensional directions. To investigate the mechanism of an inductive effect of HGF/SF on the invasiveness of SKG-IIIa, we examined the effect of HGF/SF on the expression of intercellular adhesion molecule E-cadherin, cell-substrate adhesion molecules CD44, alpha2beta1, and alpha6beta1, and intracellular skeleton fiber actin in SKG-IIIa in cell enzyme-linked immunosorbent assay (ELISA) and immunofluorescence staining.

RESULTS

HGF/SF messenger RNA (mRNA) was detected in stromal cells, and c-met mRNA was detected in SKG-IIIa and Hela-S3. Hela-S3 that initially showed weak intercellular contact freely invaded the Matrigel-coated multiporous membrane without the addition of HGF/SF. In contrast, SKG-IIIa that initially showed strong intercellular adhesion could invade the membrane after the addition of HGF/SF. The same results were represented by an addition of HECD-1, an anti-human E-cadherin antibody. In an experiment with cell culture in a thick Matrigel layer, control SKG-IIIa showed a mirror-ball-like invasion pattern, whereas HGF/SF-stimulated SKG-IIIa spread horizontally over the membrane and migrated through the membrane holes, presenting a tentacular invasion pattern. Migration of SKG-IIIa under the membrane was confirmed by scanning and transmission electron microscopy. The addition of HGF/SF in cell ELISA assay decreased the expression of E-cadherin and actin in SKG-IIIa, but it did not change the expression of CD44, alpha2beta1, and alpha6beta1. Immunofluorescence staining revealed that the expression of E-cadherin in cell membrane was disturbed by HGF/SF.

CONCLUSIONS

Our data indicate that HGF/SF produced by stromal cells influences the mode of stromal invasion of squamous cervical cancer by selectively decreasing the expression of both E-cadherin and actin.

The role of leukocytes during acute phase inflammation in crystalline silica-induced lung injury

Silicosis is characterized by progressive granulomatous and fibrogenic response in the lung. Inhaled crystalline silica (Qt) induces activation of pulmonary macrophages and leukocyte infiltration in the lung of Qt-treated animals. We investigated the role of leukocyte infiltration and L-selectin during the acute phase of inflammation in developing chronic lung injury in Qt-treated rats. Seventy Wistar male rats were treated with a single transtracheal instillation of Qt (25 mg/kg). Rats were treated intraperitoneally with anti L-selectin monoclonal antibody (mAb), F(ab')2 HRL-3 (HRL-3, a blocking mAb), or RF(ab')2 HRL-2 (HRL-2, a non-blocking mAb)for 4 days before and after Qt injection. Administration of HRL-3 reduced approximately 50% of leukocyte infiltration in the BAL, whereas HRL-2 treatment prior to Qt stimulation showed time-dependent increase of BAL leukocytes. CINC and GRO levels as well as peripheral blood cell counts were similar in HRL-2- or HRL-3-treated animals in the first 4 days of the study. Three months after Qt treatment, extensive granuloma-containing macrophages and leukocytes developed in the lung of the HRL-3-treated rats as compared with the HRL-2-treated rats. Ratio of CD4+ to CD8+ T cells in granulomas did not differ between the HRL-3 and HRL-2 groups. Results suggest that an early phase of leukocyte activation was diminished by blocking L-selectin with the antibody, but treatment with anti-L-selectin increased the formation of granulomas in the Qt-treated rats.

A nanometer-sized high-spin polyradical: poly(4-phenoxyl-1,2-phenylenevinylene) planarily extended in a non-Kekulé fashion and its magnetic force microscopic images

A pi-conjugated, but non-Kekulé- and nondisjoint-type poly(1,2-phenylenevinylene) network bearing 4-substituted di-tert-butylphenoxyls was synthesized through a one-pot polycondensation of the star-shaped subpart and the subsequent oxidation, which was persistent even at room temperature. The polyphenoxyl radical with a spin concentration of 0.4 displayed an average S of 10/2. The polyradical with the molecular weight of 3.2 x 10(4) gave a disklike image of ca. 35 x 0.6 nm with both an atomic and a magnetic force microscopy: the molecular image was examined as a nanoscale and single-molecular-based magnetic dot.

CD44 binds a chondroitin sulfate proteoglycan, aggrecan

Here we report that CD44 binds a chondroitin sulfate (CS) proteoglycan, aggrecan, a major component of cartilage. Soluble CD44-IgG and CD44(+) cells bound to aggrecan from rat chondrosarcoma and bovine cartilage, immobilized on microtiter plates. In both cases, binding was blocked by a neutralizing anti-CD44 mAb or by the pretreatment of aggrecan with chondroitinase, but not hyaluronidase or keratanase, indicating that CD44 binds aggrecan in a manner dependent on CS side chains of aggrecan and that hyaluronic acid is not involved in the binding. Structural analysis showed that glycosaminoglycans of aggrecan from rat chondrosarcoma and bovine articular cartilage consist of mainly CS A and a mixture of CS A and C respectively. When immobilized on microtiter plates, both CS A and C bound CD44-IgG, and the reaction was specifically inhibited by an anti-CD44 mAb. In addition, aggrecan augmented apoptosis in cells expressing CD44-Fas chimeric molecules in synergy with a non-blocking anti-CD44 mAb IRAWB14.4, suggesting that CD44-aggrecan interaction can induce oligomerization of the chimeric molecules. These results suggest that aggrecan interacts with CD44 to mediate cell adhesion and to trigger oligomerization of CD44 molecules, which may lead to intracellular signaling.

[Molecular mechanisms underlying cell adhesion--molecules mediating lymphocyte migration]

Adhesion molecules play crucial roles in a variety of in vivo responses such as development of various tissues in embryos and also in the body defence mechanism in the postnatal period. Defects in adhesion molecules thus result in various pathological disorders. Recent investigation has identified a large number of novel adhesion molecules, particularly those involved in the extravasation of leukocytes including lymphocytes. However, there still appears to be a substantial number of unidentified adhesion molecules. In addition, signal transduction as well as regulatory mechanisms of adhesion molecules remain not fully explored. I will herein describe general characteristics of adhesion molecules and also discuss issues that need to be urgently resolved in the field of cell adhesion.

Versican interacts with chemokines and modulates cellular responses

We previously reported that versican, a large chondroitin sulfate proteoglycan, isolated from a renal adenocarcinoma cell line, ACHN, binds L-selectin. Here we report that versican also binds certain chemokines and regulates chemokine function. This binding was strongly inhibited by the chondroitinase digestion of versican or by the addition of soluble chondroitin sulfate (CS) B, CS E, or heparan sulfate. Furthermore, these glycosaminoglycans (GAGs) could bind directly to the chemokines that bind versican. Thus, versican appears to interact with chemokines via its GAGs. We next examined if versican or GAGs affect secondary lymphoid tissue chemokine (SLC)-induced integrin activation and Ca(2+) mobilization in lymphoid cells expressing a receptor for SLC, CC chemokine receptor 7. Interestingly, whereas heparan sulfate supported both alpha(4)beta(7) integrin-dependent binding to mucosal addressin cell adhesion molecule-1 (MAdCAM-1)-IgG and Ca(2+) mobilization induced by SLC, versican or CS B inhibited these cellular responses, and the extent of inhibition was dependent on the dose of versican or CS B added. These findings suggest that different proteoglycans have different functions in the regulation of chemokine activities and that versican may negatively regulate the function of SLC via its GAG chains.

Simultaneous treatment of multiple primary cancers of the oral cavity and other sites

Multiple primary cancers are not uncommon in the head and neck region. Since the time for treatment will be prolonged if each lesion is treated separately, simultaneous treatment of the cancers is preferred to ensure complete remission of lesions and increased survival of patients. In this paper, the efficacy of combined treatment was evaluated in 9 patients with oral cancers and concurrent cancers in other sites. The mean age of the patients was 54 years (range 44 to 66). The tongue (8) and mandible (1) were the sites of involvement. Concurrent cancers were found most often in the esophagus, followed by stomach and lung. Histologically, 7 lesions were diagnosed as squamous cell carcinomas. All oral cancers were treated by surgery. Neck dissection and simultaneous reconstruction were performed in 5 patients. In addition, concurrent cancers were treated simultaneously by endoscopic mucosal resection in 2 patients and radical resection followed by immediate reconstruction in 6 other patients. However, simultaneous surgical treatment of all lesions could not be performed in an individual with 3 cancers. The time of surgery ranged from 23 minutes to 17 hours and 30 minutes. With the exception of 2 patients who died of postoperative complications and had needed treatment for dysphasia, all patients were discharged after 1 to 2 months. Four of the patients are still alive 2 years and 6 months after surgery. These results indicate that simultaneous treatment is effective in selected cases of multiple cancers.

Binding of a large chondroitin sulfate/dermatan sulfate proteoglycan, versican, to L-selectin, P-selectin, and CD44

Here we show that a large chondroitin sulfate proteoglycan, versican, derived from a renal adenocarcinoma cell line ACHN, binds L-selectin, P-selectin, and CD44. The binding was mediated by the interaction of the chondroitin sulfate (CS) chain of versican with the carbohydrate-binding domain of L- and P-selectin and CD44. The binding of versican to L- and P-selectin was inhibited by CS B, CS E, and heparan sulfate (HS) but not by any other glycosaminoglycans tested. On the other hand, the binding to CD44 was inhibited by hyaluronic acid, chondroitin (CH), CS A, CS B, CS C, CS D, and CS E but not by HS or keratan sulfate. A cross-blocking study indicated that L- and P-selectin recognize close or overlapping sites on versican, whereas CD44 recognizes separate sites. We also show that soluble L- and P-selectin directly bind to immobilized CS B, CS E, and HS and that soluble CD44 directly binds to immobilized hyaluronic acid, CH, and all the CS chains examined. Consistent with these results, structural analysis showed that versican is modified with at least CS B and CS C. Thus, proteoglycans sufficiently modified with the appropriate glycosaminoglycans should be able to bind L-selectin, P-selectin, and/or CD44.

Effects of nasal continuous positive airway pressure on soluble cell adhesion molecules in patients with obstructive sleep apnea syndrome

PURPOSE

Obstructive sleep apnea syndrome is common in middle-aged men and may be associated with an increased risk of cardiovascular disease. We investigated the effect of nasal continuous positive airway pressure (CPAP) treatment on levels of soluble cell adhesion molecules-which have been shown to be associated with the development of atherosclerosis-in these patients.

SUBJECTS AND METHODS

We studied 23 patients with obstructive sleep apnea syndrome diagnosed by polysomnography who were treated with nasal CPAP. Serum soluble intercellular adhesion molecule-1, E-selectin, and vascular cell adhesion molecule-1 levels were measured before nasal CPAP was started, and after 3 or 4 days (n = 19), 1 month (n = 23), or 6 months (n = 11) of treatment.

RESULTS

After 3 to 4 days of nasal CPAP therapy, the mean (+/- SD) soluble E-selectin level had decreased from 89 +/- 44 ng/mL to 69 +/- 28 ng/mL (P = 0.002). After 1 month, the soluble intercellular adhesion molecule-1 level had decreased from 311 +/- 116 ng/mL to 249 +/- 74 ng/mL (P = 0.02). After 6 months, soluble vascular cell adhesion molecule-1 levels had not changed significantly, while the mean soluble intercellular adhesion molecule-1 level (212 +/- 59 ng/mL) had decreased further (P = 0.02). Before treatment, soluble intercellular adhesion molecule-1 levels and the apnea and hypopnea index were correlated (r = 0.43, P = 0.04).

CONCLUSIONS

Obstructive sleep apnea and hypopnea have a significant adverse effect on serum soluble cell adhesion molecule-1 levels that may be reduced by nasal CPAP treatment.

Intercellular adhesion molecule 1 mediates mononuclear cell infiltration into rat glomeruli after renal ablation

Mononuclear cells, primarily macrophages and lymphocytes, infiltrate the renal glomeruli and are involved in the progression of various glomerular diseases. Intercellular adhesion molecule 1 (ICAM-1) is expressed on the vascular endothelium and mediates the infiltration of leukocytes into the site of inflammation. Although the expression of ICAM-1 can be induced by the stimulation of inflammatory cytokine, ICAM-1 expression can also be induced by such nonimmune mechanisms as shear stress. Glomerular hyperfiltration is a major mechanism that contributes to the progression of the glomerular sclerosis that results from the loss of functioning nephrons. In the present study, we examined the role of ICAM-1 for mononuclear cell infiltration in the glomeruli of the five-sixth nephrectomized rat as a model of glomerular hyperfiltration. The fluorescence intensity score of the staining for ICAM-1 in the glomeruli of the five-sixth nephrectomized rats was significantly increased as compared with that in the control (sham-operated) rats at 1 week (1.51 +/- 0.15 vs. 0.61 +/- 0.13; p < 0.01) and 2 weeks (1.31 +/- 0.17 vs. 0.51 +/- 0.09; p < 0.01). The number of leukocytes present in the glomeruli was significantly increased in the five-sixth nephrectomized rats compared with control (sham-operated) rats at 1 week (3.44 +/- 0.16 vs. 0.99 +/- 0.08; p < 0.01) and 2 weeks (3.14 +/- 0.14 vs. 0.89 +/- 0.07; p < 0.01). Leukocytes mainly consisted of macrophages in the five-sixth nephrectomized rats at 1 week (2.39 +/- 0.19) and 2 weeks (1.46 +/- 0.11). Anti-ICAM-1 monoclonal antibody effectively prevented the infiltration of macrophages into the glomeruli following nephrectomy. These results indicate that glomerular hyperfiltration may be involved in the induction of the expression of ICAM-1 and the infiltration of macrophages into the renal glomeruli following glomerular injury.

Antibody-induced modulation of the leukocyte CD11b integrin prevents mild but not major renal ischaemic injury

BACKGROUND

CD11/CD18 beta(2) integrins are involved in leukocyte adhesion to the activated endothelium, and therefore represent a possible therapeutic target in the prevention of ischaemic acute renal failure (ARF).

METHODS

To assess the effect of an anti-CD11b monoclonal antibody (mAb) in ischaemic ARF, uninephrectomized Fischer rats were subjected to 45 or 60 min of warm renal ischaemia, then received 1 mg of anti-CD11b mAb 5 min before reperfusion.

RESULTS

After 45 min of ischaemia, renal function tests at 24 and 48 h were less altered in mAb-treated than in control rats, but after 60 min of ischaemia the same level of renal insufficiency was observed in the two groups. In parallel, milder tubular necrosis and less leukocyte infiltration were observed in the treated group after 45 min of ischaemia, but no difference was seen after 60 min compared to the control group. The mAb was detected on blood neutrophils up to 48 h after infusion and a marked down-regulation of CD11b expression on neutrophil surfaces was documented by flow cytometry.

CONCLUSION

These results indicate that anti-CD11b mAb administered prior to reperfusion decreases moderate ischaemic ARF but fails to prevent renal injury secondary to prolonged ischaemia in this model.

Narrative approach to ethics education for students without clinical experience

Niigata University School of Medicine has provided three courses in which medical ethics (ME) is taught to students who have little or no clinical experience. To evoke student's imagination, we have developed a "narrative approach" to learn ME using cases. Prior to a case analysis, students are required to exchange their own life history regarding the core issues in the case. A case is presented not only in the traditional form of vignette, but also in the form of narrative. In the narrative, the case is a story composed of personal narratives, collected and edited from diaries, letters, interviews of persons involved. Our experience suggests that the principle-based reasoning using simple vignettes is often hardly accomplished by students. However, the narrative approach was found to be useful since students can: (1) gain more accurate and wide comprehension of medical and psycho-social aspects of the case; (2) grasp the nature and the history of the conflicting views among persons in the case; (3) find more easily any method for dealing with and settling problems; and (4) exchange viewpoints with patients and their family.

Prediction of diabetes in Biobreeding/Aburahi rats by the measurement of soluble L-selectin

L-selectin was initially identified as a homing receptor, recently soluble L-selectin has been used as a marker of the inflammation. Therefore, we investigated the relation between the development of diabetes and serum L-selectin levels in the Biobreeding (BB) rats. Serum L-selectin were measured from 30 days old to the onset of diabetes or to 90 days old in Biobreeding (BB) rats and Wistar Furth (WF) rats. Significant elevation of L-selectin was found in diabetes prone (DP) rats from 45 days old to the onset of diabetes or through 90 days old. No elevation was found in other strain of rats. In histological study, all of DP rats had insulitis and no other strain of rats had it. Therefore, we conclude that the measurement of serum L-selectin could be useful tool to predict the onset of diabetes or presence of insulitis in BB rats.

ADAMTS-1 cleaves a cartilage proteoglycan, aggrecan

A disintegrin-like and metalloproteinase with thrombospondin type I motifs-1 (ADAMTS-1) is an extracellular matrix-anchored metalloproteinase. In this study we have demonstrated that ADAMTS-1 is able to cleave a major cartilage proteoglycan, aggrecan. N-terminal sequencing analysis of the cleavage product revealed that ADAMTS-1 cleaves the Glu(1871)-Leu(1872) bond within the chondroitin sulfate attachment domain of aggrecan. In addition, deletional analysis demonstrated that the C-terminal spacer region of ADAMTS-1 is necessary to degrade aggrecan. These results suggest that ADAMTS-1 may be involved in the turnover of aggrecan in vivo.