Possible association of nicotinic acetylcholine receptor gene (CHRNA4 and CHRNB2) polymorphisms with nicotine dependence in Japanese males: an exploratory study.

INTRODUCTION: Smoking is a leading global cause of avoidable mortality. It has been reported that the nicotinic acetylcholine receptor (CHRNA4 and CHRNB2) genes might be associated with smoking behavior in several ethnic populations. However, no study between the 2 genes and nicotine dependence (ND) using a Japanese population has been reported. METHODS: We examined the association between ND and 5 single nucleotide polymorphisms (SNPs) within the CHRNA4 and 3 SNPs within the CHRNB2 using a well characterized sample of 558 Japanese healthy male workers with a relatively homogeneous background. The Fagerström test for nicotine dependence (FTND) was used to quantify the degree of ND. Additionally, we explored the effect of gene-gene interactions of the 2 genes on ND. RESULTS: We found CHRNB2 rs4845652 genotypes to be associated with FTND scores under an additive genetic model: rs4845652 T-allele carriers had lower ND levels (p=0.038; when adjusted for smoking duration: p=0.052). Furthermore, we demonstrated a possible gene-gene interaction of CHRNA4 and CHRNB2 on ND in a dose-dependent manner: those smokers with CHRNA4 rs1044397 GG or GA genotypes along with CHRNB2 rs4845652 CC genotype are likely to demonstrate higher ND scores. DISCUSSION: These findings suggest that CHRNB2 rs4845652 T-allele carriers may be associated with lower levels of ND, and that certain allelic combinations of CHRNA4 and CHRNB2 might be correlated with higher ND levels. This preliminary study has certain limitations (issues such as sample size/power and multiple testing) that need to be taken into account, and the present work thus has an experimental nature.

Sonographic demonstration of human small intestinal migrating motor complex phase III.

BACKGROUND: Migrating motor complex phase III (MMC phase III) of intestine is an important physiological mechanism traditionally recognized by myoelectric recordings or pressure tracings. Direct imaging is difficult and sonographic visualization in human has not been reported. METHODS: We have demonstrated this unique phenomenon in three patients who underwent abdominal sonographic examinations. Characteristic images were recorded by videotape and both spatial and temporal features were analyzed. KEY RESULTS: Occurrences of multiple equally spaced, rhythmic intestinal contractions were observed. Parameters including wave frequency, propagation velocity, and duration of the events agreed with those of the well-known phase III. The presence of distinct cyclic patterns observed in two and abolition by meal in the other patient further support our conclusion. CONCLUSIONS & INFERENCES: We conclude that the migrating waves observed in our study represent the human MMC phase III. This unique finding in human subjects merits further investigation.

Histopathological and biochemical changes following fat embolism with administration of corn oil micelles: a new animal model for fat embolism syndrome.

Several experimental models have been used to produce intravascular fat embolism. We have developed a simple technique to induce fat embolism using corn oil emulsified with distilled water to form fatty micelles. Fat embolism was produced by intravenous administration of these fatty micelles in anaesthetised rats, causing alveolar oedema, haemorrhage and increased lung weight. Histopathological examination revealed fatty droplets and fibrin thrombi in the lung, kidney and brain. The arteriolar lumen was filled with fatty deposits. Following fat embolism, hypoxia and hypercapnia occurred. The plasma phospholipase A(2), nitrate/nitrite, methylguidanidine and proinflammatory cytokines were significantly increased. Mass spectrometry showed that the main ingredient of corn oil was oleic acid. This simple technique may be applied as a new animal model for the investigation of the mechanisms involved in the fat embolism syndrome.

Nicotinamide abrogates acute lung injury caused by ischaemia/reperfusion.

Poly (ADP-ribose) synthase or polymerase (PARS and PARP, respectively) is a cytotoxic enzyme which causes cellular damage. Nicotinamide, a compound of vitamin B complex, has been reported to exert an inhibitory effect on PARS or PARP. The present study tests the effects of nicotinamide on acute lung injury and associated alterations following ischaemia/reperfusion (I/R) of the isolated perfused rat's lung. I/R increased the lung weight (LW) to body weight ratio, LW gain, protein and dye tracer leakage, pulmonary arterial pressure and capillary permeability. The insult also increased nitrate/nitrite, methyl guanidine, tumour necrosis factor-alpha and interleukin-1beta in lung perfusate, while it decreased adenosine triphosphate content with an increase in PARP activity in lung tissue. Most of the I/R-induced changes were abrogated by post-treatment (30 min after I/R) with nicotinamide (100 mg.kg(-1) body weight). However, the increase in pulmonary arterial pressure was enhanced by nicotinamide post-treatment. Following I/R, the inducible nitric oxide synthase (iNOS) mRNA expression was enhanced. Nicotinamide reduced the iNOS expression. The results suggest that nicotinamide exerted a protective effect on the acute lung injury caused by ischaemia/reperfusion. The mechanisms may be mediated through the inhibition on the poly (adenosine diphosphate-ribose) polymerase activity, inducible nitric oxide synthase expression and the subsequent suppression of nitric oxide, free radicals and pro-inflammatory cytokines with restoration of adenosine triphosphate.

Ischemia/reperfusion-induced low reactivity of the rat superior mesenteric vascular bed is associated with expression of nitric oxide synthases.

UNLABELLED: Our objective was to investigate the mRNA and protein expressions of eNOS and iNOS in the mesenteric vascular bed after ischemia and reperfusion of the rat superior mesenteric artery (SMA) and the role of nitric oxide (NO) in the response of the vascular bed to vasoconstrictors following reperfusion of the SMA. METHODS: Real-time polymerase chain reaction and immunohistochemistry were used to monitor the mRNA and protein expression of eNOS and iNOS after I/R challenge to the rat SMA. Ischemia was induced by clamping the SMA for 40 minutes, after which the flow was restored and the vessels were reperfused for 300 minutes. Blood samples were collected for assays of lactic dehydrogenase, tumor necrosis factor (TNF), hydroxyl radical, and NO. After ischemia/reperfusion, the vascular beds were separated for analysis of the expression of eNOS and iNOS. The SMA with its associated intestinal tissue was isolated and perfused in vitro with Tyrode's solution (N = 8) then challenged with phenylephrine. RESULTS: Reperfusion of the SMA induced an increase in blood concentrations of lactic dehydrogenase (P < .001; N = 8), hydroxyl radical (P < .05), TNF (P < .001), and NO (P < .05). ENOS and iNOS mRNA expression increased 1.3 +/- 0.1-fold and 19.6 +/- 3.5-fold, respectively when compared to the sham-operated group. Protein expression increased 1.9 +/- 0.4-fold and 12.6 +/- 3.1-fold, respectively, after reperfusion (N = 3) when compared with sham-treated rats. In vitro challenge showed that administration of phenylephrine (10(-8) approximately 10(-4) nmol) produced vasoconstriction in a dose-related manner. Maximum contractile responses to phenylephrine were attenuated in reperfused SMA. Addition of the NOS inhibitor N(G)-nitro-L-arginine (L-NNA, 10(-4) M) resulted in full recovery of the response to phenylephrine. CONCLUSIONS: Ischemia/reperfusion of the SMA results in a decrease in vascular reactivity of the mesenteric vessels that is dependent on NOS expression by the intestinal vascular bed.

Lack of a protective effect of insulin on three reperfusion-liver injury models in rats and mice.

UNLABELLED: Our objective was to investigate the potential protective effects of insulin on the liver injury induced in three ischemia and reperfusion (I/R) models. METHODS: Three I/R models were used: (1) I/R of the liver was produced in isolated, perfused rat livers; (2) in in situ I/R of the liver in rats, ischemia was induced by clamping off the hepatic artery and portal vein for 40 minutes, the flow then restored, and the liver reperfused for 90 minutes; (3) in in situ I/R of the liver in mice, ischemia was induced by clamping off the hepatic artery for 15 minutes, the flow then restored, and the liver reperfused for 45 minutes. In all three cases, blood samples collected before ischemia and after reperfusion were analyzed for sGOT. Plasma nitrate/nitrite, hydroxyl radicals, and tumor necrosis factor were also measured. In each model, a dose of insulin sufficient to induce euglycemia was administered to assess its protective effect on liver injury and inflammation. RESULTS: These I/R protocols resulted in a significant increase in sGOT and in three inflammatory parameters; nitric oxide, hydroxyl radicals, and tumor necrosis factor. Pretreatment with insulin did not attenuate the liver injury in any of the three I/R models. CONCLUSIONS: Although insulin has been reported to provide anti-inflammatory benefits by reducing oxidative and nitrosative stress and cytokine release, none of these protective effects was seen in the three I/R-induced liver injury models we tested.

Compulsive exercise acutely upregulates rat hippocampal brain-derived neurotrophic factor.

This study was to examine the effects of treadmill exercise on the expression of brain-derived neurotrophic factor (BDNF) in rat hippocampus. After 1-wk treadmill familiarization, animals in exercise groups received a 4-wk exercise training or an acute exercise. They were sacrificed 2 h or 2 d after exercise and their hippocampal BDNF mRNA and protein levels were determined. We demonstrated that 1) hippocampal BDNF mRNA and protein levels were both elevated in response to exercise training at 2 h after the last run but not after 2 d; 2) an acute moderate exercise (1 or 3 d) increased BDNF protein levels; 3) acute severe exercise increased BDNF protein and mRNA levels in animals under a familiarization regimen, while suppressed the BDNF mRNA level in rats without treadmill familiarization, paralleling the stress effect of immobilization/water exposure. We conclude that compulsive treadmill exercise with pre-familiarization acutely upregulates rat hippocampal BDNF gene expression.

Oxygen radicals and matrix metalloproteinases mediate reperfusion liver injury.

Many pathological processes involve the breakdown and remodeling of the extracellular matrix, which is mediated by the family of important enzymes known as matrix metalloproteinases (MMPs). One such process is warm ischemia/reperfusion (I/R) injury, the most important cause of dysfunction of liver allografts. We monitored protein expression of MMP-9 by Western blotting in rat liver after I/R. We also monitored changes in total MMP activity in the serum before and after I/R. Ischemia was induced by clamping the common hepatic artery and portal vein for 40 minutes and reperfusing for 90 minutes. Blood samples collected before ischemia and after reperfusion were analyzed for AST, hydroxyl radical, and tumor necrosis factor (TNFalpha). This protocol resulted in a high level of MMP-9 expression in liver tissue. Total MMP activity in serum was also significantly increased. Levels of AST, hydroxyl radicals, and TNF alpha were concomitantly increased. Ilomastat, an MMP inhibitor, attenuated the I/R-induced liver injury. After administration of the oxygen radical scavenger N-acetylcysteine (NAC), total MMP activity was suppressed, and liver injury was again attenuated. These results indicated that reperfusion liver injury induced an increase in MMP-9 protein expression and in serum MMP activity. The protective effects of an MMP inhibitor and NAC indicate that oxygen radical production is involved in MMP expression and liver injury associated with I/R.

Epidermoid cysts of the testes in Taiwanese men.

Epidermoid cyst is a rare benign tumor of the testes. The records from the last 20 years of Taiwanese patients in whom a testicular tumor was diagnosed were reviewed retrospectively. Patients with a confirmed epidermoid cyst of testis were evaluated for age, clinical assessment and follow-up. Among a total 146 testicular tumors, 28 (19%) patients had a benign tumor including 15 patients (10%; mean age 23 years, range 17-32 years) with an epidermoid cyst diagnosed pathologically. Pre-operative suspicion of the benign nature of the lesions was supported by testicular ultrasonography in 11 patients. Seven patients underwent magnetic resonance imaging after which benign epidermoid cyst was impressed in five patients. A testicular-sparing operation was performed in 12 patients after frozen sections confirmed the diagnosis. Three patients were treated by radical orchiectomy. There was no relapse after a median follow-up of 42 months (range, 2-82 months). Ultrasonography and magnetic resonance imaging of the scrotum may allow the diagnosis of epidermoid cyst of the testes to be made pre-operatively. The absence of relapse in these patients further supports the use of organ sparing surgery in these young men.

Value of prostate-specific antigen in the staging of Taiwanese patients with newly diagnosed prostate cancer.

Records of 71 patients diagnosed with prostate cancer were reviewed retrospectively regarding clinical stage, prostate-specific antigen (PSA), Gleason score, CT scan of pelvis, bone scan, and pelvic lymph node dissection. Fourteen patients had pelvic lymphadenopathy based on the CT scan. Of these, no patient had a PSA level <4 ng/mL, 1 patient had a PSA level between 4 and 10 ng/mL, and 3 had a PSA level between 10 and 20 ng/mL. Twelve of 13 patients with positive bone scan results had a PSA level >20 ng/mL, and 1 patient had a PSA level between 10 and 20 ng/mL. PSA can be cost-effective in selecting and identifying appropriate staging for patients with newly diagnosed prostate cancer. CT scans are not indicated in men with clinical localized prostate cancer when PSA levels are < or =10 ng/mL. Bone scan is not required for staging asymptomatic men with PSA levels of < or =20 ng/mL. Pelvic lymphadenectomy for localized prostate cancer may not be necessary if PSA levels is < or =20 ng/mL and Gleason score is < or =5.

Brain region-dependent increases in beta-amyloid and apolipoprotein E levels in hypercholesterolemic rabbits.

Recent studies indicate a possible link between serum cholesterol level, beta-amyloid (Abeta) peptide concentrations, and the incidence of Alzheimer's disease (AD). In the present report, the effects of dietary cholesterol on Abeta and apolipoprotein E (APOE) levels in several brain regions were examined using diet-induced hypercholesterolemic rabbits as the animal model. Increased dietary cholesterol levels increased Abeta concentrations in temporal cortex (p = 0.02). A similar trend was observed in the frontal cortex (p = 0.06), yet not in the cerebellum. Interestingly, the regional levels of Abeta in the hypercholesterolemic rabbit paralleled the amyloid pathology observed in AD brain. Elevated APOE levels were also noticed in temporal (p < 0.01) and frontal (p < 0.01) cortices, but not in cerebellum, in the rabbit fed with cholesterol-abundant diet. These results suggest that high serum cholesterol levels could induce the elevation of brain APOE, which may play a role in aggravating the Abeta accumulation.

Change in International Prostate Symptom Score after transurethral prostatectomy in Taiwanese men with benign prostate hyperplasia: use of these changes to predict the outcome.

To investigate whether the pre- and postoperative International Prostate Symptom Score (IPSS) change predicts the outcome of transurethral prostatectomy in a Taiwanese population, 99 patients (transurethral prostatectomy candidates) were assessed with the IPSS before and 6-12 months after surgery. All symptoms improved significantly postoperatively. Patients with a greater preoperative IPSS benefited the most. Improvements in preoperative obstructive symptoms (incomplete emptying, intermittency, straining, and weak stream) were greater than those in irritable symptoms (urgency, frequency, and nocturia). A significant correlation was found between IPSS and quality of life (QOL) before and after transurethral prostatectomy. A change of 1 unit on the IPSS scale was found to decrease the QOL score 0.282 units. The positive predictive value of a >or=7-IPSS point decrease depended on the predictive IPSS criteria applied. When the preoperative IPSS was more than 17, the sensitivity was 83.5% and specificity was 30%. Postoperative improvement did not differ significantly between acute urinary retention (AUR) and non-AUR patients. Change in IPSS of more than 7 points predicted symptomatic improvement with high sensitivity. The predictive value depends on the definition of significant improvement (magnitude of IPSS change) and on the level of IPSS symptoms (sufficient to warrant transurethral prostatectomy).

Intrascrotal hemangioma.

Although hemangiomas are the most common benign tumors in infancy, scrotal hemangiomas are extremely rare and comprise less than 1% of all hemangiomas. Scrotal hemangiomas that extend into adjacent areas of the perineum, thigh, or anterior abdominal wall may occasionally be seen. Ultrasound is recommended as part of the preoperative assessment delineating the extent of a scrotal hemangioma. Since an absence of flow on Doppler studies does not exclude the diagnosis of hemangioma, MRI (magnetic resonance imaging) may provide more useful information for differentiation. In cases of cutaneous scrotal hemangiomas, conservative treatment that waits for involution is widely accepted. In patients with scrotal masses, exploration with excision is the treatment of choice even if a hemangioma is likely. The authors report a case of an intrascrotal tumor diagnosed preoperatively by color duplex ultrasonography and MRI in a 19-year-old male who subsequently underwent en bloc excision. Pathological examination identified a cavernous hemangioma.

Aggressive angiomyxoma of the scrotum.

Aggressive angiomyxoma is a rare and nonmetastasizing soft tissue tumor of the pelvis and perineum and occurs almost exclusively in adult females. It infiltrates locally and has a high risk of local recurrence. Recommended treatment of the symptomatic patient is wide excision with tumor-free margins and close postoperative monitoring. Herein, a case of aggressive angiomyxoma in an adult male is described, which arose in the scrotum over 12 months. The tumor showed an intermediate signal on T1-weighted MRI images. Contrast-enhanced T1-weighted images showed good enhancement. Wide excision of the tumor was performed. The surgical specimen measured 7 x 5 x 5 cm in size and weighed 80 g. The tumor's surface was smooth and had a gelatinous cut surface. Grossly, it was encapsulated with a pleura-like membrane and had a finger-like projection. Microscopically, sections showed many walled vessels of various sizes, collagen fibrils, a loose myxoid background. and spindle stroma cells. MRI and CT showed the angiomatous and myxomatous nature of the tumor wall. To the authors' knowledge, this is the first report to describe MRI findings in scrotal angiomyxoma.

The protective effect of niacinamide on ischemia-reperfusion-induced liver injury.

Reperfusion of ischemic liver results in the generation of oxygen radicals, nitric oxide (NO) and their reaction product peroxynitrite, all of which may cause strand breaks in DNA, which activate the nuclear enzyme poly(ADP ribose)synthase (PARS). This results in rapid depletion of intracellular nicotinamide adenine dinucleotide and adenosine 5'-triphosphate (ATP) and eventually induces irreversible cytotoxicity. In this study, we demonstrated that niacinamide, a PARS inhibitor, attenuated ischemia/reperfusion (I/R)-induced liver injury. Ischemia was induced by clamping the common hepatic artery and portal vein of rats for 40 min. Thereafter, flow was restored and the liver was reperfused for 90 min. Blood samples collected prior to I and after R were analyzed for methyl guanidine (MG), NO, tumor necrosis factor (TNF-alpha) and ATP. Blood levels of aspartate transferase (AST), alanine transferase (ALT) and lactate dehydrogenase (LDH) which served as indexes of liver injury were measured. This protocol resulted in elevation of the blood NO level (p < 0.01). Inflammation was apparent, as TNF-alpha and MG levels were significantly increased (p < 0.05 and p < 0.001). AST, ALT and LDH were elevated 4- to 5-fold (p < 0.001), while ATP was significantly diminished (p < 0.01). After administration of niacinamide (10 mM), liver injury was significantly attenuated, while blood ATP content was reversed. In addition, MG, TNF-alpha and NO release was attenuated. These results indicate that niacinamide, presumably by acting with multiple functions, exerts potent anti-inflammatory effects in I/R-induced liver injury.

Hypotensive effects of captopril on physical properties of the arterial system in young and adult rats.

We determined the acute effects of the angiotension converting enzyme inhibitor captopril on the arterial mechanics in rats at different ages, based on the exponentially tapered T-tube model. Male Wistar-Kyoto rats aged 4 and 12 months were individually referred to as young (n = 8) and adult rats (n = 8) and were anesthetized and thoractomized. The pulsatile aortic pressure and flow signals before and after the administration of captopril (20 mg/kg, i.p.) were measured by a high-fidelity pressure sensor and an electromagnetic flow probe, respectively. In each age group, captopril showed little change in basal heart rate as well as cardiac output. However, captopril produced a drop of 15% in mean aortic pressure in young and a fall of 12% in adult rats. In addition. captopril reduced total peripheral resistance by 21% in young and by 23% in adult animals. As for the pulsatile nature of the arterial system, captopril had increased wave transit time of the lower body circulation of 10% in young and of 12% in adult rats. By contrast, captopril reduced wave reflection factor by 22% in young and by 25% in adult animals. In conclusion, the converting enzyme inhibitor captopril has a stiffness-decreasing effect on Windkessel vessels and a dilated effect on resistance arterioles in either young or adult rats. No age dependence of vascular response and reflex tachycardia to captopril has been found in rats between 4 and 12 months.

The expression of neuropeptides in hyperplastic and malignant prostate tissue and its possible clinical implications.

PURPOSE: We characterized the incidence and pattern of distribution of neuroendocrine differentiated tumor cells in prostatic hyperplastic and carcinomatous tissue, correlated neuroendocrine differentiation with prostate specific antigen (PSA) and assessed whether neuroendocrine cells have value as an independent indicator of poor prognosis in patients with prostate carcinoma. MATERIALS AND METHODS: We immunohistochemically evaluated hyperplastic and carcinomatous prostate specimens for chromogranin A, neuron specific enolase and serotonin expressing tumor cells. The expression of various markers in cells was analyzed and correlated with tumor DNA ploidy, disease grade and stage, PSA and clinical course in patients with prostate cancer. RESULTS: Enrolled in our study were 31 patients with hyperplastic prostate tissue and 30 with prostatic carcinoma. Followup in cancer cases was 1 to 9 years (mean 3.7). During followup 9 patients (30%) died of cancer. We noted DNA content aneuploidy in 5 cases (16.7%) of prostate carcinoma. Chromogranin A, neuron specific enolase and serotonin were expressed in 80%, 43% and 77% of cases of prostate carcinoma and in 29%, 10% and 36% of hyperplastic tissue, respectively. Larger prostates had no higher content of various neuroendocrine cells than smaller prostates. There was higher expression of neuropeptides in carcinomatous than in hyperplastic tissue. Of the 3 peptides chromogranin A was significantly related to all parameters, including Gleason score, tumor stage, PSA and patient survival. In addition to PSA, neuron specific enolase was also closely associated with other clinicopathological parameters. Serotonin was significantly related to patient survival only but we noted no correlation with Gleason score, tumor stage or PSA. In regard to factors predictive of patient prognosis expression of the 3 neuropeptides in tumor cells, Gleason score, tumor stage and PSA were closely related to patient survival in this study CONCLUSIONS: The growth of hyperplastic prostate tissue is related to neuroendocrine cell activity. The chromogranin A marker has the highest expression in prostate cancer. Neuroendocrine cells may represent an independent indicator of poor prognosis in patients with prostate carcinoma.

The lung is the major site that produces nitric oxide to induce acute pulmonary oedema in endotoxin shock.

1. The present study was undertaken to determine the locus of nitric oxide (NO) production that is toxic to the lung and produces acute pulmonary oedema in endotoxin shock, to examine and compare the effects of changes in lung perfusate on endotoxin-induced pulmonary oedema (EPE) and to evaluate the involvement of constitutive and inducible NO synthase (cNOS and iNOS, respectively). 2. Experiments were designed to induce septic shock in anaesthetized rats with the administration of Escherichia coli lipopolysaccharide (LPS). Exhaled NO, lung weight (LW)/bodyweight (BW) ratio, LW gain (LWG) and lung histology were measured and observed to determine the degree of EPE 4 h following LPS. The EPE was compared between groups in which LPS had been injected either into the systemic circulation or into the isolated perfused lung. The lung perfusate was altered from whole blood to physiological saline solution (PSS) with 6% albumin to test whether different lung perfusions affected EPE. Pretreatment with various NOS inhibitors was undertaken 10 min before LPS to investigate the contribution of cNOS and iNOS to the observed effects. 3. Endotoxin caused profound systemic hypotension, but little change in pulmonary arterial pressure. The extent of EPE was not different between that induced by systemic injection and that following administration to isolated lungs preparations. Replacement of whole blood with PSS greatly attenuated (P < 0.05) EPE. In blood-perfused lungs, pretreatment with NOS inhibitors, such as Nomega-nitro-L-arginine methyl ester, aminoguanidine and dexamethasone, significantly prevented EPE (P < 0.05). 4. The major site of NO production through the whole blood is in the lung. The NO production mediated by the iNOS system is toxic to the endothelium in the pulmonary microvasculature. Inhalation of NO for patients with sepsis may be used with clinical caution. Therapeutic consideration of lung extracorporeal perfusion with PSS and pharmacological pretreatment with iNOS inhibitors may be warranted.

Severe exercise enhances phagocytosis by murine bronchoalveolar macrophages.

Because physical activity affects the immune competency of individuals by an unknown mechanism, we investigated the effect of acute exercise on phagocytosis of bronchoalveolar macrophages (BAMs). Male BALB/c mice, 7-9 weeks old, ran on a treadmill to exhaustion (severe exercise, SE) or at a final speed of 17 m/min for 30 min (moderate exercise, ME). Although both exercise protocols induced differential leukocytosis, 95% leukocytes from lung lavages of both groups were BAMs. The BAM phagocytic capacity of nonopsonized beads increased immediately after SE but not after ME, gradually returning to the basal level after 4 h. SE upregulates the macrophage scavenger receptors (SR-A type I/II and MARCO), CR3, and ICAM-1, but not Fc gammaR. Although the blocking effect of MARCO antibody was most pronounced, that of ICAM-1 antibody was totally reversed by cross-linking CR3. Our results showed that SE, but not ME, activated BAMs and that the enhanced nonopsonized phagocytosis was mainly mediated by scavenger receptors and ICAM-1/CR3.

Endothelial [Ca(2+)](i) signaling during transmigration of polymorphonuclear leukocytes.

Vascular endothelium plays an important role in regulating the transendothelial migration of polymorphonuclear leukocytes (PMNs). In this study, the intracellular calcium ion ([Ca(2+)](i)) signaling of endothelial cells (ECs) during PMN transmigration was examined at the single-cell level. Human umbilical vein ECs were cultured on a thin layer of collagen gel. The ECs were labeled with fura-2, immersed in formyl-Met-Leu-Phe, and subsequently perfused with fresh buffer to establish a gradient of chemoattractant across the EC monolayer. The entire process of PMN rolling on, adhering to, and transmigrating across the EC monolayer was recorded under both phase-contrast and fluorescence optics. The data showed the following: (1) At high concentration (approximately 3 x 10(6)/mL), both PMN suspension and its supernatant stimulated frequent EC [Ca(2+)](i) elevations across the monolayer; (2) when used at lower concentration (approximately 5 x 10(5)/mL) to avoid the interference of soluble factors, PMN transmigration, but not rolling or adhesion, was accompanied by EC [Ca(2+)](i) elevation; (3) the latter EC [Ca(2+)](i) elevation occurred simultaneously in ECs adjacent to the transmigration site, but not in those that were not in direct contact with the transmigrating PMNs; (4) this EC [Ca(2+)](i) elevation was an initial and required event for PMN transmigration; and (5) PMNs pretreated with 5,5'-dimethyl-1, 2-bis(2-aminophenoxy)ethane-N, N, N', N'-tetraacetic acid transmigrated with the accompanying EC [Ca(2+)](i) elevation, but they became elongated in the collagen gel. In conclusion, PMNs induce adjacent EC [Ca(2+)](i) signaling, which apparently mediates the "gating" step for their subsequent transmigration. (Blood. 2000;96:3816-3822)