Expression of intercellular adhesion molecule-1 on rat cardiac myocytes by monocyte chemoattractant protein-1

OBJECTIVE

Cytokine induction of intercellular adhesion molecule-1 (ICAM-1) on cardiac myocytes may be a critical step in cardiac inflammation associated with acute myocardial infarction and myocarditis. The aim of this study was to investigate the involvement of monocyte chemoattractant protein-1 (MCP-1), a homologue of mouse JE, in the neutrophil-myocyte adhesion in vitro.

METHODS

MCP-1/JE and ICAM-1 mRNA expression in cultured neonatal rat cardiac myocytes was evaluated by northern blot analysis. ICAM-1 molecule content on myocytes was determined by ELISA. For adherence assay, myocytes and neutrophils were co-incubated and the number of bounded neutrophils was counted.

RESULTS

MCP-1/JE transcripts were not clearly observed in cultured neonatal rat cardiac myocytes; however, its transcripts were clearly detected by exposure to interleukin 1 alpha (100 U.ml-1), lipopolysaccharide (1 microgram.ml-1), or hypoxia (95% N2 + 5% CO2). In ELISA analysis, the expression of ICAM-1 molecules on cardiac myocytes was significantly stimulated by MCP-1 in a dose dependent manner, and the effect of MCP-1 was observed as early as at 6 h. In northern blot analysis, ICAM-1 mRNA expression was constitutively observed in myocytes, and the expression was markedly stimulated by exposure to MCP-1 with a peak elevation at 2 h. In adherence assay, MCP-1 stimulated the adhesion of rat neutrophils to rat cardiac myocytes, and this effect of MCP-1 was inhibited by an anti-ICAM-1 MAb.

CONCLUSIONS

These results suggest that cardiac myocytes produce MCP-1, which could in turn promote the adhesion of neutrophils to myocytes via ICAM-1 expression, suggesting the involvement of MCP-1 in cardiac inflammation associated with acute myocardial infarction and myocarditis.

Involvement of adhesion molecules in human monocyte adhesion to and transmigration through endothelial cells in vitro

Although the accumulation of monocyte-derived foam cells in the subendothelium is a key step in early atherogenesis, the mechanism responsible for monocyte adhesion to and subsequent transmigration through endothelial cells (ECs) has not been defined fully. We investigated the kinetics and the role played by adhesion molecules in the adhesion and transmigration of human monocytes using an in vitro three-dimensional model system comprising ECs cultured on collagen gels. Monocyte adhesion to untreated EC layers increased with time, reached a maximum after 3 h, and then declined. Monocyte transmigration through untreated EC layers also increased with time and reached a plateau after 3-4 h. Prestimulation of ECs with interleukin-1 beta (IL-1 beta; 25 U/ml) for 4 h enhanced monocyte adhesion (40.7 +/- 1.4%) and transmigration (37.9 +/- 1.6%) significantly compared with the value for untreated EC layers. In unstimulated EC layers, anti-leukocyte function-associated antigen-1 (LFA-1) plus anti-intercellular adhesion molecule-1 (ICAM-1) monoclonal antibodies (mAbs) inhibited monocyte adhesion and transmigration significantly by 19% and 20%, respectively, whereas anti-very late antigen-4 (VLA-4) plus anti-vascular cell adhesion molecule-1 (VCAM-1) mAbs did not. In IL-1 beta-stimulated EC layers, anti-LFA 1 plus anti-ICAM-1 mAbs inhibited the adhesion and transmigration by 32% and 30%, respectively and anti-VLA-4 plus anti-VCAM-1 mAbs did so by 18% and 27%, respectively. These results suggest that the monocyte-EC interaction in unstimulated ECs is mediated, in part, by the LFA-1-ICAM-1 pathway and in IL-1 beta-stimulated ECs, in part, by both LFA-1-ICAM-1 and VLA-4-VCAM-1 pathways.

Immunolocalization of glucose transporter GLUT1 in the rat placental barrier: possible role of GLUT1 and the gap junction in the transport of glucose across the placental barrier

GLUT1 is an isoform of facilitated-diffusion glucose transporters and has been shown to be abundant in cells of blood-tissue barriers. Using antibodies against GLUT1, we investigated the immunohistochemical localization of GLUT1 in the rat placenta. Rat placenta is of the hemotrichorial type. Three cell layers (from the maternal blood side inward) cytotrophoblast and syncytiotrophoblasts I and II, lie between the maternal and fetal bloodstreams. GLUT1 was abundant along the invaginating plasma membrane facing the cytotrophoblast and the syncytiotrophoblast I. Also, the infolded basal plasma membrane of the syncytiotrophoblast II was rich in GLUT1. Apposing plasma membranes of syncytiotrophoblasts I and II, however, had only a small amount of GLUT1. Numerous gap junctions were seen between syncytiotrophoblasts I and II. Taking into account the localization of GLUT1 and the gap junctions, we suggest a possible major transport route of glucose across the placental barrier, as follows: glucose in the maternal blood passes freely through pores of the cytotrophoblast. Glucose is then transported into the cytoplasm of the syncytiotrophoblast I via GLUT1. Glucose enters the syncytiotrophoblast II through the gap junctions. Finally glucose leaves the syncytiotrophoblast II via GLUT1 and enters the fetal blood through pores of the endothelial cells.

Novel mechanism of glucocorticoid-mediated gene repression. Nuclear factor-kappa B is target for glucocorticoid-mediated interleukin 8 gene repression

A glucocorticoid, dexamethasone, inhibited the production of a leukocyte chemotactic cytokine, interleukin 8 (IL-8), as well as mRNA expression by a glioblastoma cell line, T98G, stimulated with interleukin 1 (IL-1). Dexamethasone also inhibited IL-8 promoter-driven chloramphenicol acetyltransferase (CAT) activities induced by IL-1, suggesting that dexamethasone inhibited IL-8 production mainly at the transcriptional level. Moreover, CAT assay revealed that the nuclear factor-kappa B (NF-kappa B) binding site was the crucial cis-element required for conferring IL-1 responsiveness in conjunction with the CCAAT enhancer binding protein/nuclear factor-IL-6 (NF-IL6) and/or the AP-1 binding site(s). Mutation of either the AP-1 or NF-IL6 binding site did not abolish IL-8 gene repression by dexamethasone, suggesting that these sites were not targets for dexamethasone. Trimerized kappa B sequence in the IL-8 gene was enough for conferring the induction by IL-1 and inhibition by dexamethasone of CAT activity. Finally, dexamethasone diminished the IL-1-induced formation of NF-kappa B complexes, which were identified immunochemically to consist of p50 and p65, without reducing the amount of translocated factors. Collectively, dexamethasone interfered with the binding of the most essential transcription factor, NF-kappa B, to its cognate cis-element, thereby suppressing the transcription of IL-8 gene.

Induction of metallothionein in astrocytes by cytokines and heavy metals

Immunohistochemical staining of human and rat brains for metallothionein (MT) using a monoclonal anti-MT antibody (MT45) revealed that protoplasmic astrocytes, which are densely localized in the gray matter, contain high levels of MT. Human U373MG astrocytoma cells were stimulated with interleukin (IL)-1 or heavy metals to produce MT. When expression of MT in U373MG cells was analyzed by Northern blotting or indirect immunofluorescence using the MT45 antibody, it was found that IL-1 (> or = 10 U/ml), CdCl2 (50 microM) and high concentrations of ZnCl2 (500 microM) induced marked biosynthesis of MT.IL-6 (up to 3,000 U/ml) and lower concentrations of ZnCl2 (10-50 microM), however, showed little inducing activity. Hippocampal astrocytes in primary culture produced a relatively high basal level of MT. The MT level increased in response to addition of IL-1 (> or = 10 U/ml), ZnCl2 (50 microM) and CdCl2 (5 microM). However, the increase induced by IL-6 (1,000 U/ml) was not very marked. The in vivo induction of MT in the brain by cytokines is not fully understood. However, our data and other indirect evidence suggest that IL-1 may be a potent stimulator of MT induction in astrocytes. Furthermore, the astrocytoma cell line, U373MG, is a suitable in vitro system to analyze the expression of MT in astrocytes.

Coronary artery ectasia with annuloaortic ectasia

A 50-year-old Japanese woman with annuloaortic ectasia was found to have total coronary artery ectasia without evident atherosclerosis. The coronary ectasia may have been secondary to or of similar etiology to the annuloaortic ectasia. There was neither stigmata of Marfan's syndrome nor any sign of dissection of the ascending aorta or coronary arteries. Furthermore, the patient was not elderly, and had no hyperlipidemia, diabetes mellitus, or history of smoking. There was a marked blood pressure difference between the arms, and linear calcification was present in the aortic wall. A stenotic lesion was present in the right mid-subclavian artery. Although it is impossible to rule out atherosclerosis as the etiology of these findings, the possibility that they may be a manifestation of Takayasu's arteritis is discussed.

[Usefulness of Dornier MPL9000 lithotriptor with new optional fluoroscopic guiding system (electrode X 155: depth 15.5cm) in treatment of urinary tract stone]

The Dornier MPL9000 lithotriptor was originally equipped with an ultrasound guiding system. Recently an optional fluoroscopic guiding system was developed to overcome the known disadvantages of the ultrasound system and to exploit the merits of both systems by using them in combination. Herein, we examined the effectiveness and safety of this new optional system. From December 1990 to February 1991, we treated 41 patients with upper urinary tract stones with MPL9000 using the optional fluoroscopic system. Treatments were judged as effective if the patients were stone-free or the residual fragments were smaller than 4mm in diameter. The overall effectiveness rates at one month after the treatment were 54.5% for renal stones and 76.9% for ureter stones respectively. At three months after the treatment the effectiveness rate for renal stones was 83.3%, and that for ureter stones 95.5%. The changes in the laboratory data after the treatment were alight and caused no clinical problems. Complications during and after the treatment were also minor and tolerable. MPL9000 was sufficiently effective and safe in the treatment of upper urinary tract stones when it was used the new optional fluoroscopic system instead of the original ultrasonic guiding system.

Interleukin-8 production by CD16-CD56bright natural killer cells in the human early pregnancy decidua

Decidual CD16-CD56bright natural killer (NK) cells were sorted from the decidual mononuclear cells (MNC) at the early pregnancy using a fluorescence activated cell sortor. The CD16-CD56bright NK cell population occupies a major population in the decidual MNC, in contrast to a very small population (< 1%) in the peripheral blood MNC. These decidual CD16-CD56bright NK cells produced a large amount of IL-8, i. e., mean of 96.7 +/- 19.8 ng/ml in the 24 hr-cultured supernatants without any stimulant, which was comparable to the IL-8 production by LPS-stimulated peripheral blood MNC. Most of the IL-8 was ascribable to the production from decidual CD16-CD56bright NK cells. Intracytoplasmic IL-8 in the decidual CD56bright NK cells was also detected by flow cytometry. RT-PCR methods confirmed IL-8 mRNA expression in this population, while no or very scarce expression of IL-1 alpha and IL-1 beta mRNA was observed. The present study is a first observation revealing that decidual CD16-CD56bright NK cells express IL-8 mRNA and produce IL-8.

Essential involvement of interleukin-8 in neutrophil recruitment in rabbits with acute experimental arthritis induced by lipopolysaccharide and interleukin-1

Rheumatoid arthritis and related inflammatory joint diseases are characterized by massive infiltration of polymorphonuclear cells (PMN) into inflamed joints. Interleukin-8 (IL-8) has recently been identified as a leukocyte chemotactic and activating factor produced by activated tissue cells as well as monocytes/macrophages. Examination was made of the involvement of IL-8 in acute arthritis induced by injecting lipopolysaccharide (LPS) or interleukin-1 alpha (IL-1 alpha) into the joints of rabbits. The neutralizing antibody to rabbit IL-8 blocked almost completely the infiltration of PMN into the joints and provided protection from damage to tissue in the early phase of inflammation induced by LPS or IL-1 alpha. Mononuclear cell infiltration observed later was not inhibited by this antibody. This is the first paper to clearly demonstrate that IL-8 is an essential and major mediator determining whether PMN infiltration will occur in the early phase of experimental acute arthritis.

Protection against lethal bacterial infection in mice by monocyte-chemotactic and -activating factor

Chemotactic factors regulate the recruitment of neutrophils, lymphocytes, or monocytes-macrophages to infectious and inflammatory sites. The purpose of this study was to determine whether monocyte-chemotactic and -activating factor (MCAF [MCP-1], a JE gene product) also influences the host defense mechanism against microbial infection. We evaluated the effect of recombinant human MCAF on the survival rate of mice systemically infected with Pseudomonas aeruginosa or Salmonella typhimurium. The administration of 2.5 micrograms of MCAF 6 h before infection completely protected the mice from lethal infection. Mice with cyclophosphamide-induced leukopenia exhibiting increased susceptibility to P. aeruginosa were also endowed with resistance by the same dose of MCAF. Administration of MCAF at -6 h was critical, since MCAF given either earlier or later than -6 h failed to rescue mice from lethal infection. The in vivo effect on the survival of mice paralleled the reduced recovery of viable P. aeruginosa or S. typhimurium from the peritoneal cavity, i.e., the number of recovered bacteria from the MCAF (2.5 micrograms per mouse)-treated mice was reduced to less than 2% of control mice for P. aeruginosa and 4% of control mice for S. typhimurium at 24 h. Since MCAF exhibited chemotaxis on murine macrophages as well as enhanced phagocytosis and killing of bacteria in vitro, the activation of macrophages, followed by the recruitment into the peritoneal cavity, is responsible for eliminating bacteria and thus enhancing the survival rate.

Development of diabetic nephropathy in Japanese patients with insulin-dependent diabetes mellitus: Tokyo Women's Medical College epidemiologic study

To clarify the development of diabetic nephropathy in Japanese insulin-dependent diabetes mellitus (IDDM), 373 patients with IDDM who had no proteinuria at the first visit to our Diabetes Center were evaluated. The incidence of persistent proteinuria increased rapidly between 10 and 19 years of diabetes duration, and only a few new cases occurred thereafter. Patients whose ages at onset of IDDM were 9-17 years (n = 167) and 18-29 years (n = 90) had rapid development of persistent proteinuria compared to the 0 to 8-year group (n = 116) (p < 0.02 and p < 0.003, respectively). Females (n = 233) developed persistent proteinuria to a greater extent until 24 years of diabetes duration than males (n = 140) (p = 0.17). Development of proteinuria did not vary according to calendar year of diagnosis of IDDM or diabetes duration at the first visit. Renal insufficiency (serum creatinine of 2.0 mg/dL or greater) followed the onset of proteinuria; 60% of the patients with the onset of IDDM between 1951 and 1969 developed renal insufficiency 10 years after the onset of proteinuria, whereas 30% of patients with the onset of IDDM after 1970 developed this condition. Development of renal insufficiency did not vary according to sex, age at onset of IDDM, or age at onset of proteinuria. Renal failure requiring dialysis therapy occurred within 4 years after renal insufficiency. In conclusion, development of diabetic nephropathy in Japanese IDDM exhibits three stages. The onset of proteinuria appears to be influenced by age at onset of IDDM and sex.(ABSTRACT TRUNCATED AT 250 WORDS)

Nitric oxide synthesis in rat cardiac myocytes and fibroblasts

We investigated nitric oxide (NO) synthase activity in cultured neonatal rat cardiac myocytes and fibroblasts upon treatment with interleukin 1 beta (IL-1 beta) and lipopolysaccharide (LPS). Incubation of cardiac myocytes for 24 h with IL-1 beta or LPS caused a significant increase in NO and cGMP production. Simultaneous incubation of IL-1 beta with NG-monomethyl-L-arginine or transforming growth factor beta (TGF-beta) completely inhibited the IL-1 beta-induced NO and cGMP production in cardiac myocytes. In contrast, incubation of cardiac fibroblasts for 24 h with IL-1 beta or LPS showed no significant effect on NO or cGMP production. Addition of IL-1 beta decreased the beating rate of cardiac myocytes, but TGF-beta overcame that inhibition. These observations suggest the presence of iNOS in cardiac myocytes, which is an important regulator of contractile function of the heart.

Expression of intercellular adhesion molecule-1 on rat vascular smooth muscle cells by pro-inflammatory cytokines

Infiltration of mononuclear cells is an early pathological finding in human and experimental atherosclerosis. However, the cellular and molecular basis for cell infiltration is incompletely understood. While the intercellular adhesion molecule-1 (ICAM-1) is expressed on endothelial cells and promotes the adhesion of mononuclear cells, there is little information on the expression of ICAM-1 on vascular smooth muscle cells (SMC). In this study, we investigated the expression of ICAM-1 on cultured rat SMC and its regulation by pro-inflammatory cytokines, interleukin 1 alpha (IL-1 alpha), interleukin 6 (IL-6) and monocyte chemoattractant protein 1 (MCP-1). In immunohistochemical staining, ICAM-1 molecules were constitutively expressed on the surface of SMC. In flow cytometric and ELISA analyses, ICAM-1 molecule expression on SMC was significantly upregulated by IL-1 alpha and MCP-1, but not by IL-6, in a dose-dependent manner. The effects of IL-1 alpha and MCP-1 were observed as early as 4 h. In Northern blot analysis, ICAM-1 mRNA was slightly detectable in unstimulated SMC, but its expression was clearly observed following exposure to IL-1 alpha or MCP-1. These results suggest that ICAM-1 on SMC, as well as on endothelial cells, could participate in the focal accumulation of mononuclear cells in human atherosclerotic lesions.

Induction of inflammatory cytokines in the pleural effusion of cancer patients after the administration of an immunomodulator, OK-432: role of IL-8 for neutrophil infiltration

When OK-432, a well-known streptococcal preparation for an anti-tumour drug, was administered into the pleural cavity of patients with malignant pleurisy, a rapid and prominent leukocytosis, predominantly consisting of neutrophils, was observed in the cavity. Neutrophil infiltration usually peaked 6-9 h after OK-432 administration, and levelled down after 24 h. Prior to the neutrophil accumulation, transient but marked elevation of various inflammatory cytokine levels including IL-1 beta, TNF-alpha, IL-8 and G-CSF was observed. In particular, IL-8 levels increased more than 10-fold, while GM-CSF did not change significantly. A good correlation between IL-8 levels and neutrophil chemotactic response was observed particularly during 0-3 h. Specific neutralization or removal of IL-8 by antibody column abrogated half of the neutrophil chemotaxis, while neutralization of C5a removed around 40%. Sequential removal of IL-8 and C5a abrogated totally 80% of chemotaxis, confirming that these two factors are mostly responsible for the neutrophil chemotaxis in the pleural fluids. These results have suggested that rapid neutrophil infiltration induced by OK-432 in vivo is ascribable largely to IL-8 and in part to C5a.

Case report: a case of multiple coronary artery to left ventricular communications

A 39-year-old man with anginal pain had multiple coronary artery to left ventricular communications. His electrocardiogram showed evidence of left ventricular hypertrophy, and an echocardiogram revealed a dilated left ventricle. A coronary angiogram revealed multiple coronary artery to left ventricular fistulae involving three major coronary arteries with no evidence of atherosclerotic lesions. Only 17 cases of such fistulous communications involving three major coronary arteries have been reported in the literature. It is suggested that the fistulous communications to the left ventricle was a cause of his angina pectoris, probably because of the coronary steal phenomenon.

Induction and regulation of IL-8 and MCAF production in human brain tumor cell lines and brain tumor tissues

In order to elucidate the role of inflammatory cytokines in the central nervous system, we examined the production of two leukocyte chemoattractants, IL-8 and monocyte chemotactic and activating factor (MCAF) in brain tumor cell lines. The glioma cell lines tested exhibited high levels of IL-8 and MCAF mRNA expression upon stimulation with IL-1 or TNF-alpha, while none of the neuroblastoma cell lines expressed these cytokine mRNA. Both IL-8 and MCAF mRNA expression depended on the dose of IL-1 alpha and TNF-alpha and appeared very rapidly, reaching maximal levels at 3-6 hr, with substantial production of these cytokines in the culture supernatants. When various immunosuppressive drugs were tested, glucocorticoids but not other immunosuppressive drugs markedly inhibited the IL-1 or TNF-alpha-induced IL-8 and MCAF mRNA accumulation, suggesting that glucocorticoid is a potent regulator of these inflammatory cytokine production in the neural tissues. In addition, reverse transcription-polymerase chain reaction (RT-PCR) revealed the expression of IL-8 and MCAF mRNA expression in resected brain tumor tissues including glioblastoma, astrocytoma grade 2, ependymoma and medulloblastoma, indicating that these inflammatory cytokines are expressed in vivo.

Carotid atherosclerosis in young-aged IDDM associated with diabetic retinopathy and diastolic blood pressure

To determine whether young patients with IDDM already have atherosclerosis and what factors would relate to atherosclerosis, we examined the intimal-medial thickness (IMT) of the common carotid artery by ultrasonography. Subjects were 29 young patients with IDDM (aged 17-39 years, duration 4-31 years) without manifest macroangiopathy and 13 healthy controls of comparable age (22-29 years). The carotid artery IMT of young patients with IDDM were significantly higher than those of controls (0.60 +/- 0.09 vs. 0.46 +/- 0.02 mm, P < 0.0001). The levels of IMT significantly correlated to diastolic blood pressure (r = 0.45, P < 0.02), and were higher in those with proliferative retinopathy than those without retinopathy (0.66 +/- 0.09 vs. 0.55 +/- 0.08 mm, P < 0.02). The levels of IMT showed no significant correlation to the attained age, duration of IDDM, HbA1c, systolic blood pressure, and cholesterol level. These findings suggest the usefulness of this examination for the early detection of diabetic macroangiopathy, and point to a close relationship between microangiopathy and macroangiopathy in IDDM.

Expression of c-kit mRNA and protein during the differentiation of human hematopoietic progenitor cells

To investigate how c-kit and c-kit ligand play a role in the function of hematopoietic stem cells, we determined the expression of c-kit in sorted human hematopoietic stem cells, CD34+CD33- cells and CD34+CD33+ cells. CD34+ cells constituted approximately 1% of the population of gated bone marrow cells and contained colony-forming cells. Two-color analysis by a fluorescence-activated cell sorter (FACS) revealed that about one-third to one-half of the total CD34+ cell population were positive for the CD33 antigen. To analyze the relative accumulation of c-kit mRNA in sorted cells, we used the reverse transcription-polymerase chain reaction (RT-PCR) method, followed by Southern blot analysis. There was a linear relationship between the amount of input RNA and products amplified in the range of 10(3) to 10(5) cells. Using this procedure, we carried out an analysis of c-kit mRNA expression in CD34+CD33-, CD34+CD33+, CD34-CD33+, and CD34-CD33- cells. Enhanced expression for c-kit mRNA was observed solely in CD34+CD33- cells. In contrast, flow cytometry shows that c-kit protein was expressed most abundantly in CD34+CD33+ cells. Colony-forming cells were generated on a human stromal cell layer for 5 weeks initiated with CD34+CD33- cells but not with CD34+CD33+ cells. During co-culture with stromal cells, CD34+CD33- cells differentiated into CD34+CD33+ cells. From these findings, it is concluded that CD34+CD33+ cells are direct progenies of CD34+CD33- cells. In this differentiation pathway, the expression of c-kit mRNA decreased and the c-kit protein increased.

Passive immunization with anti-parathyroid hormone-related protein monoclonal antibody markedly prolongs survival time of hypercalcemic nude mice bearing transplanted human PTHrP-producing tumors

Malignancy-associated hypercalcemia is mainly caused by excessive production of parathyroid hormone-related protein (PTHrP) by the tumor. Using anti-PTHrP-(1-34) monoclonal murine antibody (anti-PTHrP MoAb), we studied whether repeated injection of the homologous antibody would continuously decrease the serum calcium concentration in hypercalcemic nude mice bearing transplanted human PTHrP-producing tumors, leading to prolongation of their survival time. Daily SC injections of anti-PTHrP MoAb decreased the serum calcium concentration almost to within the normal range in nude mice bearing transplanted human PTHrP-producing tumors (T3M-1, EC-GI, PC-3, and FA-6) but not in a nude mouse bearing a transplanted parathyroid carcinoma. The antibody did not affect FA-6 tumor growth either in vitro or in vivo. Pancreatic carcinoma cells (FA-6), which caused the most severe hypercalcemia, were inoculated into 6-week-old nude mice. When severe hypercalcemia (approximately 19 mg/dl) had developed, daily SC injection of anti-PTHrP MoAb was started. Within 18 days of this time point, all untreated tumor-bearing mice (n = 10) died of hypercalcemia and cachexia, whereas all the treated mice (n = 10) showed an increase in body weight and survived for at least 25 days. Histologic examination of the treated mice revealed a marked decrease in osteoclastic bone resorption, without toxicologic findings in the kidney and liver. These results suggest that passive immunization against PTHrP can continuously ameliorate the hypercalcemia and markedly prolong the survival time of severely hypercalcemic, tumor-bearing mice. If a human monoclonal antibody against PTHrP-(1-34) could be developed, then passive immunization would be potentially one of the most effective therapies for patients with malignancy-associated hypercalcemia due to excessive production of PTHrP.

Expression of recombinant rabbit IL-8 in Escherichia coli and establishment of the essential involvement of IL-8 in recruiting neutrophils into lipopolysaccharide-induced inflammatory site of rabbit skin

In order to establish the pathophysiological roles of IL-8, rabbit IL-8 was expressed in Escherichia coli and purified to homogeneity by sequential chromatography on heparin agarose, CM-HPLC, and RP-HPLC. The purified recombinant rabbit IL-8 was homogeneous on SDS-PAGE and the ED50 of neutrophil chemotactic activity for rabbit peritoneal neutrophils was 2 ng/ml. The binding of 125I-labeled rabbit IL-8 to rabbit neutrophils was inhibited by unlabeled human IL-8 as well as rabbit IL-8 but not by another leucocyte chemotactic cytokine (chemokine), monocyte chemotactic and activating factor. Scatchard plot analysis of the binding of 125I-labeled rabbit IL-8 to rabbit peritoneal neutrophils revealed that the rabbit neutrophils have two affinity classes of receptors for IL-8 (Kd = 2.3 nM, 4.1 x 10(4) sites/cell; Kd = 18.0 nM, 11.4 x 10(4) sites/cell). It was found that a previously generated mouse anti-human IL-8 mAb, WS-4, inhibited the binding of 125I-labeled rabbit IL-8 to rabbit neutrophils, and blocked neutrophil chemotaxis in vitro in a specific and dose-dependent manner. An ELISA system for rabbit IL-8 was established using this mAb and guinea pig polyclonal antibodies to recombinant rabbit IL-8 to measure the levels of IL-8 in rabbit plasma. Intravenous administration of lipopolysaccharide (LPS) (100 micrograms) in rabbits caused the highest level of IL-8 in blood at around 2 h. Intravenous administration of WS-4 (10 mg) inhibited neutrophil infiltration at the site of LPS injection into the rabbit skin, suggesting that IL-8 is essential in the recruitment of neutrophils at sites of acute inflammation in vivo.

[Changes in renal blood flow after treatment with ESWL in patients with renal stones. Studies using ultrasound color Doppler method]

Recently several authors have observed tissue damages in ESWL treated kidneys, such as interstitial hemorrhage and edema, cavitation of renal tubular cells and vascular spasms. Examination using renal scintigraphy suggested that these damages could cause a decrease of renal blood flow in the treated kidney. Trying to confirm and further investigate this possibility, we studied on changes of renal blood flow velocity using ultrasound color doppler method in 23 consecutive patients with renal stones who underwent ESWL. The studies were conducted before, immediately after and 1 week after an ESWL treatment. Results were as follows; renal blood flow velocity decreased significantly in the area exposed to shock were immediately after the treatment and returned to the pretreatment levels after 1 week. The changes were not significant in the non-exposed area. In parallel with this decrease of renal blood flow velocity, significant increases of resistive index, pulsatility index and significant decreases of ratio were observed. These parameters calculated by measuring of renal blood flow velocity are known to well correlate with parenchymal vascular resistance. We speculate that these changes in renal parenchymal blood flow velocity are triggered by the tissue damages caused by the exposure to shock wave. The recovery of renal blood flow velocity may depend on the recovery of the tissue damages. Ultrasound color doppler method may make it possible to monitor the recovery of tissue damages induced by shock wave and may provide us with an useful information to determine when to repeat ESWL if needed.

Involvement of central opioidergic and nonopioidergic neuroendocrine systems in the suppressive effect of acupuncture on delayed type hypersensitivity in mice

The effect of a single treatment of electroacupuncture (Acu) at early or late stages of the efferent phase on 2, 4, 6-trinitrochlorobenzene (TNCB)-induced delayed type hypersensitivity (DTH) was studied in intact and hypophysectomized (HPX) mice. Acu (2.5 Hz, 15 min) applied to the acu-point equivalent to GV4 at 0, 3, 18 or 21 h after TNCB challenge induced significant suppression (45-73%) of the maximal extent of ear swelling at 24 h after TNCB challenge. An immunosuppressive and antiinflammatory drug, prednisolone 10 mg/kg i.p., also suppressed the DTH to the same extent. Pretreatment with intracisternal injection of naloxone hydrochloride (2 micrograms) significantly blocked the Acu-evoked DTH suppression when Acu treatment was done at 0 or 3 h. On the contrary, naloxone did not block the effect of Acu treatment given at 21 h. In order to examine the potential involvement of the pituitary in the suppression of DTH by Acu, the DTH reaction was examined in HPX mice. Acu failed to produce suppressive response in the HPX mice unless given at 0 h. These findings indicate that Acu treatment at acu-point GV4 during the efferent phase of induced DTH can suppress the DTH through central opioidergic or nonopioidergic systems. The pituitary is apparently pivotal in this immunosuppression and it is suggested that the DTH suppression by Acu may be mediated via activation of the neuroendocrine system.

Purification and characterization of a 3,5,3'-L-triiodothyronine-specific binding protein from bullfrog tadpole plasma: a homolog of mammalian transthyretin

We analyzed the nature of the thyroid hormone-binding proteins in bullfrog plasma using N-bromoacetyl-[125I]T3 as an affinity labeling probe. Polyacrylamide gel electrophoresis under nondenaturing conditions of the bullfrog N-bromoacetyl-[125I]T3-labeled plasma proteins revealed two proteins with specific binding to T3. A labeled protein that migrated faster than albumin (T-T3BP) was detected only in plasma obtained from tadpoles at stages earlier than, but not at the end of, metamorphic climax. Another protein that migrated more slowly than albumin appeared in the plasma at the late climax stage and was present in the adult stage. To study the function of T-T3BP during metamorphosis, it was purified from tadpole plasma to the single protein. The molecular mass of this protein was estimated to be 56 kilodaltons by gel filtration, but only 16 kilodaltons by sodium dodecyl sulfate-polyacrylamide gel electrophoresis, which indicates that the molecule comprised four identical subunits. The amino acid composition of T-T3BP and the amino acid sequence of its N-terminal portion were highly homologous with those of mammalian transthyretins. These molecular features indicate that T-T3BP is a homolog of mammalian transthyretins. However, in contrast to mammalian transthyretins, the affinity of bullfrog transthyretin for T3 was 360 times higher than that for T4. Scatchard analysis revealed that T-T3BP possessed a single class of T3-binding site, with a Kd of 0.67 nM at 0 C. These results suggest that bullfrog transthyretin may play an important role in transporting T3 in the blood during metamorphosis.