Relationship between the changes in blood flow and volume in the finger during a Braille character discrimination task

PURPOSE

We hypothesized that skin blood flow (SBF) of fingers are modulated during concentrated finger perception and that the changes in SBF reflect fluctuations in finger volume (FV). The aim of this study, therefore, was examine the relationship between the changes in SBF and FV during Braille reading.

METHODS

We measured SBF of the finger, cutaneous vascular conductance (CVC), FV, and arterial blood pressure during Braille reading performed under blind conditions in thirty healthy subjects. The subjects were instructed to read a flat plate with raised letters (Braille reading) for 15 seconds using their forefinger, and to touch a blank plate as a control for the Braille discrimination procedure.

RESULTS

Arterial blood pressure slightly increased during Braille reading but remained unchanged during the touching of the blank plate. SBF, CVC, and FV were reduced during Braille reading (decreased by -26%, -29%, and -0.3 mL/100 mL respectively). Furthermore, a significant relationship was observed between the changes in SBF and FV (r=.613) during Braille reading.

CONCLUSION

These results suggested that SBF of fingers is modulated during concentrated finger perception, and that the variability of blood flow reflects the response in FV.

Caries-related Bacteria and Cytokines Induce CXCL10 in Dental Pulp

Marked infiltration of inflammatory cells, such as activated T-cells, is observed in the progression of pulpitis; however, little is known about the mechanism of their recruitment into pulpal lesions. It has been recently demonstrated that CXC chemokine ligand 10 (CXCL10) chemoattracts CXC chemokine receptor 3 (CXCR3)-positive activated T-cells. We therefore examined whether CXCL10 is involved in the pathogenesis of pulpitis. CXCL10 mRNA expression levels in clinically inflamed dental pulp were higher than those in healthy dental pulp. Immunostaining results revealed that CXCL10 was detected in macrophages, endothelial cells, and fibroblasts in inflamed dental pulp, and that CXCR3 expression was observed mainly on T-cells. Moreover, cultured dental pulp fibroblasts produced CXCL10 after stimulation with live caries-related bacteria, peptidoglycans, and pro-inflammatory cytokines. In contrast, heat-killed bacteria did not induce CXCL10 secretion. These findings suggest that CXCL10-CXCR3 may play an important role in the pulpal immune response to caries-related bacterial invasion. Abbreviations: CXCL10, CXC chemokine ligand 10; CXCR3, CXC chemokine receptor 3; IFN, interferon; FBS, fetal bovine serum; LTA, lipoteichoic acid; PGN, peptidoglycan; IL, interleukin; TNF, tumor necrosis factor; PBS, phosphate-buffered saline; ELISA, enzyme-linked immunosorbent assay; CCL, C-C chemokine ligand; TLR, Toll-like receptor; NOD, nucleotide oligomerization domain; HDPF, human dental pulp fibroblasts.

Proinflammatory effects of muramyldipeptide on human gingival fibroblasts

BACKGROUND AND OBJECTIVE

Because human gingival fibroblasts (HGFs) are the predominant cells in periodontal tissues, we hypothesized that HGFs are contributed to receptors for components of bacteria. In this study, we focused on expression and function of nucleotide binding oligomerization domain 2 (NOD2) in HGFs, which is a mammalian cytosolic pathogen recognition molecule.

MATERIAL AND METHODS

Expression of NOD2 in HGFs was examined by reverse transcriptase-polymerase chain reaction (RT-PCR) and flow cytometry. Production of interleukin (IL)-6, IL-8, cc chemokine ligand2, cxc chemokine ligand10 (CXCL10) and CXCL11 from HGFs was examined by enzyme-linked immunosorbent assay (ELISA). We used RT-PCR and immunohistochemistry to detect the NOD2 expression in human gingival tissues.

RESULTS

We found clear NOD2 expression in HGFs. Upon stimulation with NOD2 agonist, muramyldipeptide (MDP), production of proinflammatory cytokines was enhanced. Moreover, MDP-induced production of proinflammatory cytokines was inhibited in a different manner by mitogen-activated protein kinase inhibitors and phosphatidylinositol 3-kinase inhibitor. Furthermore, MDP enhanced CXCL10 and CXCL11 productions by tumor necrosis factor-alpha (TNF-alpha)- or interferon-gamma (IFN-gamma)-stimulated HGFs, although MDP alone did not induce these chemokines. TNF-alpha and IFN-gamma increased NOD2 expression in HGFs. In addition, we detected NOD2 expression in mononuclear cells and HGFs in periodontally diseased tissues.

CONCLUSION

These findings indicate that MDP which induces production of cytokines and chemokines from HGFs is related to the pathogenesis of periodontal disease.

The Effect of Dexmedetomidine on Agitation during Weaning of Mechanical Ventilation in Critically ill Patients

Ventilated patients receiving opioids and/or benzodiazepines are at high risk of developing agitation, particularly upon weaning towards extubation. This is often associated with an increased intubation time and length of stay in the intensive care unit and may cause long-term morbidity. Anxiety, fear and agitation are amongst the most common non-pulmonary causes of failure to liberate from mechanical ventilation. This prospective, open-label observational study examined 28 ventilated adult patients in the intensive care unit (30 episodes) requiring opioids and/or sedatives for >24 hours, who developed agitation and/or delirium upon weaning from sedation and failed to achieve successful extubation with conventional management. Patients were ventilated for a median (interquartile range) of 115 [87 to 263] hours prior to enrolment, Dexmedetomidine infusion was commenced at 0.4 μg/kg/hour for two hours, after which concurrent sedative therapy was preferentially weaned and titrated to obtain target Motor Activity Assessment Score score of 2 to 4. The median (range) maximum dose and infusion time of dexmedetomidine was 0.7 μg/kg/hour (0.4 to 1.0) and 62 hours (24 to 252) respectively. The number of episodes at target Motor Activity Assessment Score score at zero, six and 12 hours after commencement of dexmedetomidine were 7/30 (23.3%), 28/30 (93.3%) and 26/30 (86.7%), respectively (P <0.001 for 6 and 12 vs 0 hours). Excluding unrelated clinical deterioration, 22 episodes (73.3%) achieved successful weaning from ventilation with a median (interquartile range) ventilation time of 70 (28 to 96) hours after dexmedetomidine infusion. Dexmedetomidine achieved rapid resolution of agitation and facilitated ventilatory weaning after failure of conventional therapy. Its role as first-line therapy in ventilated, agitated patients warrants further investigation.

Human gingival fibroblasts express functional chemokine receptor CXCR6

We have reported that CXCL16, a recently discovered transmembrane chemokine, is expressed in human gingival fibroblasts (HGF). However, it is not known whether HGF express CXCR6, the receptor for CXCL16, or CXCL16 affects HGF biology. We have shown that HGF expressed CXCR6 by reverse transcription-polymerase chain reaction and flow cytometric analysis. Moreover, we elucidated that tumour necrosis factor (TNF)-alpha and cytosine-guanine dinucleotide (CpG) DNA (Toll-like receptor-9 ligand) treatment enhanced CXCR6 expression by HGF. Interleukin (IL)-4, IL-13 and CpG DNA up-regulated CXCR6 expression by TNF-alpha-stimulated HGF. On the other hand, IL-1beta and interferon-gamma inhibited CXCR6 expression on TNF-alpha-treated HGF. CXCL16 treatment induced HGF proliferation and phosphorylation of extracellular regulated kinase (ERK) and protein kinase B (AKT) in HGF. In conclusion, HGF expressed CXCR6 functionally, because CXCL16 induced HGF proliferation and ERK and AKT phosphorylation in HGF. These results indicate that CXCL16 may play an important role in the pathogenesis and remodelling in periodontally diseased tissues.

CC chemokine ligand 17 in periodontal diseases: expression in diseased tissues and production by human gingival fibroblasts

BACKGROUND AND OBJECTIVE

It has been reported that T helper 2 (Th2) cells are related to exacerbation of periodontal disease. However, it is uncertain how the migration of Th2 cells is controlled. In this study, we examined the expression of CC chemokine ligand 17 (CCL17), which is a Th2 chemokine, in periodontal tissues. Moreover, we investigated the effects of cytokines and toll-like receptor (TLR) ligands on the production of CCL17 by human gingival fibroblasts (HGFs).

MATERIAL AND METHODS

We used immunohistochemistry and reverse transcriptase-polymerase chain reaction (RT-PCR) to detect CCL17 in periodontal tissues. HGFs were exposed to cytokines and TLR ligands. Expression of CCL17 was examined by RT-PCR and enzyme-linked immunosorbent assay. We used signal transduction inhibitors in some experiments.

RESULTS

Both CCL17 and its receptor, CC chemokine receptor 4 (CCR4), were expressed in diseased periodontal tissues. A combination of tumour necrosis factor alpha (TNF-alpha) and interleukin (IL)-4/IL-13 increased CCL17 expression. Moreover, treatment of HGFs with a low dose of interferon-gamma (IFN-gamma) in combination with TNF-alpha and IL-4 or IL-13 had synergistic effects on the production of CCL17, whereas a high dose of IFN-gamma inhibited CCL17 production. Furthermore, Escherichia coli (E. coli) lipopolysaccharide (TLR4 ligand) and Pam3CSK4 (TLR2 ligand) inhibited CCL17 production by TNF-alpha + IL-4-stimulated HGFs, while CpG DNA (TLR9 ligand) enhanced TNF-alpha + IL-4 induced-CCL17 production by HGFs. Furthermore, a c-Jun NH2 terminal kinase (JNK) inhibitor, a phosphatidylinositol-3-kinase (PI3K) inhibitor and a nuclear factor kappa B (NF-kappa B) inhibitor inhibited CCL17 production by HGFs.

CONCLUSION

These results suggest that the CCL17 produced by HGFs may be involved in the migration of Th2 cells into inflamed tissues, and provide evidence that CCL17 production is controlled by cytokines and TLR ligands in periodontal disease.

Adrenomedullin suppresses tumour necrosis factor alpha-induced CXC chemokine ligand 10 production by human gingival fibroblasts

Periodontal disease is an inflammatory disorder characterized by the involvement of chemokines that are important for the recruitment of leucocytes. Several cytokines, including tumour necrosis factor alpha (TNF-alpha), are involved in regulating levels of chemokines in periodontal disease. CXC chemokine ligand 10 (CXCL10) is a chemokine related to the migration of T helper 1 cells. In this study, we examined CXCL10 expression in human gingival fibroblasts (HGFs). Moreover, we investigated the effects of adrenomedullin (AM), which is a multi-functional regulatory peptide, on the production of CXCL10 by HGFs. We revealed that TNF-alpha stimulation induced CXCL10 production by HGFs. HGFs expressed AM and AM receptors, calcitonin-receptor-like receptor (CRLR) and receptor-activity-modifying protein (RAMP) 2, mRNAs constitutively. AM treatment supressed CXCL10 production by TNF-alpha-stimulated HGFs. Moreover, we elucidated that AM produced by HGFs inhibited CXCL10 production by HGFs, because AM antagonist enhanced CXCL10 production by HGFs. TNF-alpha treatment enhanced CRLR and RAMP2 mRNA expression in HGFs. Furthermore, AM is expressed in human periodontal tissues, including both inflamed and clinically healthy tissues. These results suggest that the CXCL10 produced by HGFs may be involved in the migration of leucocytes into inflamed tissues and related to exacerbation of periodontal disease. AM might be a therapeutic target of periodontal disease, because AM can inhibit CXCL10 production by HGFs.

CXC chemokine ligand 16 in periodontal diseases: expression in diseased tissues and production by cytokine-stimulated human gingival fibroblasts

Periodontal disease is an inflammatory disorder characterized by the involvement of chemokines that are important for the recruitment of leucocytes. Several cytokines are involved in regulating levels of chemokines in periodontal disease. CXCL16 is a chemokine related to the migration of T helper 1 (Th1) cells and natural killer (NK) cells. In this study, we examined its expression in periodontal tissues. Moreover, we investigated the effects of cytokines on the production of CXCL16 by human gingival fibroblast (HGF). Reverse transcription-polymerase chain reaction (RT-PCR) analysis and immunohistochemistry revealed that CXCL16 and its receptor, CXCR6, were expressed at the mRNA and protein levels in diseased tissues. Proinflammatory cytokines [interleukin (IL)-1beta, tumour necrosis factor (TNF)-alpha and interferon (IFN)-gamma] increased the mRNA expression and release of CXCL16 in a dose-dependent manner. Moreover, treatment of HGFs with IFN-gamma in combination with IL-1beta had a synergistic effect on the production of CXCL16. On the other hand, IL-4 and IL-13 inhibited the IL-1beta-induced CXCL16 production by HGFs. Inhibitors of A disintegrin and metalloprotease (ADAM)10 and ADAM17, a recently identified protease of CXCL16, reduced the amount of CXCL16 released from HGFs. These results suggest that the CXCL16 produced by HGFs may be involved in the migration of leucocytes into inflamed tissues, and provide evidence that CXCL16 production is controlled by cytokines in periodontal disease.

Soluble products from Eikenella corrodens induce cell proliferation and expression of interleukin-8 and adhesion molecules in endothelial cells via mitogen-activated protein kinase pathways

The periodontal vasculature is profoundly affected during the progression of periodontitis, and several specific bacteria are believed to be involved in this inflammatory disease. Eikenella corrodens is one of the common bacteria detected in periodontitis diseased lesions; however, the function of this organism in periodontitis is not well understood. In this study, we investigated the E. corrodens-induced endothelial cell alteration and inflammation process that leads to leukocyte infiltration in inflamed regions. Soluble products from E. corrodens (EcSP) induced the gene expression and protein production of vascular endothelial growth factor in oral epithelial cells and human umbilical vein endothelial cells (HUVEC). Direct stimulation by EcSP also activated endothelial cell proliferation. Moreover, EcSP induced ERK1/2 (p44/42) and p38 mitogen-activated protein kinase (MAPK) phosphorylation within 10-30 min in HUVEC, as demonstrated by Western blot analysis and up-regulated intercellular adhesion molecule 1 (ICAM-1), vascular cell adhesion molecule 1 (VCAM-1), E-selectin and interleukin-8 (IL-8) production demonstrated by reverse transcription-polymerase chain reaction and enzyme-linked immunosorbent assay. The specific p38 MAPK inhibitor SB203580 reduced the expression of ICAM-1, VCAM-1 and IL-8, whereas the blockade of p44/42 by MAPK kinase (MEK1) inhibitor, PD98059, inhibited only IL-8 expression. Our results indicate that E. corrodens can trigger a cascade of events that induce inflammatory responses in periodontal tissue via the MAPK cascade and may promote chronic periodontitis without bacteria-cell contact.

Proinflammatory effects of tumour necrosis factor-like weak inducer of apoptosis (TWEAK) on human gingival fibroblasts

Tumour necrosis factor (TNF)-like weak inducer of apoptosis (TWEAK), a member of the TNF family, is a multi-functional cytokine that regulates cellular proliferation, angiogenesis, inflammation and apoptosis. In this study, we investigated TWEAK expression in periodontally diseased tissues and the effect of TWEAK on human gingival fibroblasts (HGF). Reverse transcription-polymerase chain reaction (RT-PCR) analysis and immunohistochemistry revealed that TWEAK and the TWEAK receptor, fibroblast growth factor-inducible 14 (Fn14), mRNA and protein were expressed in periodontally diseased tissues. HGF expressed Fn14 and produced interleukin (IL)-8 and vascular endothelial growth factor (VEGF) production upon TWEAK stimulation in a dose-dependent manner. The IL-8 and VEGF production induced by TWEAK was augmented synergistically by simultaneous stimulation with transforming growth factor (TGF)-beta1 or IL-1beta. IL-1beta and TGF-beta1 enhanced Fn14 expression in a dose-dependent manner. Moreover, TWEAK induced intercellular adhesion molecule-1 (ICAM-1) and vascular cell adhesion molecule-1 (VCAM-1) expression on HGF in a dose-dependent manner. The ICAM-1 expression induced by TWEAK was augmented by TGF-beta1. On the other hand, the TWEAK-induced VCAM-1 expression was inhibited by TGF-beta1. Phosphatidylinositol 3-kinase (PI3K) and nuclear factor-kappaB (NF-kappaB) inhibitor inhibit both ICAM-1 and VCAM-1 expression induced by TWEAK. However, mitogen-activated protein kinase (MEK) and c-Jun NH2-terminal kinase (JNK) inhibitor enhanced only VCAM-1 expression on HGF. These results suggest that TWEAK may be involved in the pathophysiology of periodontal disease. Moreover, in combination with IL-1beta or TGF-beta1, TWEAK may be related to the exacerbation of periodontal disease to induce proinflammatory cytokines and adherent molecules by HGF.

Extravascular Lung Water Measured Using Single Transpulmonary Thermodilution Reflects Perioperative Pulmonary Edema Induced by Esophagectomy

Pulmonary edema is the most frequent postoperative complication following esophagectomy for thoracic esophageal cancer. We enrolled 23 patients who underwent esophagectomy with extended lymph node dissection for thoracic esophageal cancer in a prospective observational clinical trial. We used the PiCCO device to measure extravascular lung water with the aim of determining whether it correlates with the respiratory index and whether it is predictive of pulmonary complications. Based on constant criteria, the tracheal tubes of 11 patients were removed on the morning of postoperative day 1 (extubation group), while 12 patients remained intubated (intubation group). These two groups significantly differed in that all patients in the extubation group recovered without any pulmonary complications, whereas 4 patients (33%) in the intubation group developed pulmonary complications. The extravascular lung water measured using PiCCO correlated significantly with the respiratory index. In the intubation group, both extravascular lung water and respiratory index were elevated 12 h after surgery and were even higher 24 h after surgery. The extravascular lung water measured using PiCCO reflects the level of postoperative pulmonary edema and predicts the pulmonary complications induced by esophagectomy with extended lymph node dissection.

Cytokines differentially regulate ICAM-1 and VCAM-1 expression on human gingival fibroblasts

The expression of intercellular adhesion molecule-1 (ICAM-1) and vascular adhesion molecule-1 (VCAM-1) on human gingival fibroblasts (HGF) may be important for migration and retention of inflammatory cells in periodontally diseased tissue. This study aimed to assess which cytokines regulate ICAM-1 and VCAM-1 expression on HGF. Tumour necrosis factor (TNF)-alpha and interferon (IFN)-gamma enhanced both ICAM-1 and VCAM-1 expression on HGF. Interleukin (IL)-1beta mainly up-regulated ICAM-1 expression. On the other hand, IL-4 and IL-13 enhanced only VCAM-1 expression on HGF. IL-10 did not modulate both ICAM-1 and VCAM-1 expression. Transforming growth factor (TGF)-beta1 enhanced ICAM-1 expression. However, TGF-beta1 inhibited the VCAM-1 expression induced by TNF-alpha or IL-4. Both ICAM-1 and VCAM-1 expression by HGF was inhibited by nuclear factor-kappaB (NF-kappaB) activation inhibitor (MG-132). Mitogen-activated protein kinases (MAPK) inhibitors did not influence ICAM-1 expression induced by TNF-alpha. Interestingly, VCAM-1 expression was enhanced by MEK inhibitor (PD98059) and c-Jun NH2-terminal kinase (JNK) inhibitor (SP600125). These results mean that the balance of cytokines in periodontally diseased tissue may be essential for control of ICAM-1 and VCAM-1 expression on HGF, and the balance of ICAM-1 and VCAM-1 expression might be important for regulation of leucocytes infiltration and retention in periodontally diseased tissue.

Increase of CCL20 expression by human gingival fibroblasts upon stimulation with cytokines and bacterial endotoxin

We have demonstrated recently that CCL20 was expressed in periodontal diseased tissues and abundant CCR6 positive T cells infiltrated in periodontally diseased tissue. However, it is uncertain which cells can elicit CCL20 production. In the present study, we examined the properties of CCL20 production by human gingival fibroblasts (HGF) culture. Here, we report that interleukin-1 beta (IL-1beta), tumour necrosis factor-alpha (TNF-alpha) and Escherichia coli lipopolysaccharide (LPS) can significantly induce the production of CCL20 by HGF. We found that TNF-alpha and E. coli LPS enhanced the production of CCL20 by HGF treated with IL-1beta. In contrast, interferon-gamma (IFN-gamma) dramatically diminished CCL20 production induced by IL-1beta. Moreover, we demonstrated that nuclear factor-kappaB (NF-kappaB), p38 mitogen-activated protein kinase (MAPK) and extracellular signal-regulated kinases (ERK) play an important role in mediating the production of CCL20 induced by IL-1beta and TNF-alpha. On the other hand, we found that not only NF-kappaB, p38 MAPK and ERK but also c-Jun NH2-terminal kinase (JNK) are involved in CCL20 production induced by E. coli LPS. Finally, we found that HGF express CCR6, CCL20 receptor, and CCL20 induced vascular endothelial growth factor (VEGF) by HGF. Taken together, these findings that HGF will be a source of CCL20 in periodontal tissue, and the CCL20 production will be controlled by proinflammatory cytokine and bacterial LPS in periodontally diseased tissue. Thus, CCL20 by HGF might be involved in inflammatory cells infiltration, and promote the progression of periodontal disease.

CXCL12 and CXCR4 expression by human gingival fibroblasts in periodontal disease

CXCL12 is a CXC chemokine that is related to lymphocyte infiltration and angiogenesis in inflammatory sites such as arthritis. However, the expression and roles of CXCL12 in periodontal disease are uncertain. The aim of this study was to assess the expression of CXCL12 and its receptor, CXCR4, in periodontal tissue and to investigate the properties of CXCL12 and CXCR4 expression by human gingival fibroblasts (HGF). RT-PCR analysis revealed that CXCL12 and CXCR4 mRNA were expressed in both normal gingival tissues and periodontal diseased tissues. Immunohistochemistry disclosed that CXCL12 was expressed and CXCR4 positive cells were found in both normal and periodontal diseased gingival tissues. Our in vitro experiments elucidated that HGF constitutively produced CXCL12, and the levels were enhanced by stimulation with tumour necrosis factor-alpha (TNF-alpha), interferon-gamma (IFN-gamma), transforming growth factor-beta (TGF-beta), regulated upon activation normal T cell expressed and secreted (RANTES) and macrophage inflammatory protein 3(alpha) (MIP-3(alpha)). On the other hand, heat killed Porphyromonas gingivalis (P. gingivalis) and P. gingivalis LPS reduced the CXCL12 production by HGF. Flow cytometry analysis clarified that CXCR4 was highly expressed on HGF, and CXCR4 expression was abrogated by TNF-alpha, IFN-gamma and P. gingivalis LPS. Moreover, CXCL12 induced vascular endothelial growth factor (VEGF) production by HGF. Our results demonstrated that CXCL12 might be related to CXCR4+ cells infiltration and angiogenesis both in normal periodontal tissues and periodontal diseased tissue. P. gingivalis, a known periodontal pathogen, inhibits the production of CXCL12 and the expression of CXCR4 by HGF. This fact means that P. gingivalis may inhibit CXCR4+ cells infiltration and neovascularization in periodontal tissue and escape from the immune response.

Expression of fractalkine (CX3CL1) and its receptor, CX3CR1, in periodontal diseased tissue

The regulatory role of chemokines and chemokine receptors on specific leucocyte recruitment into periodontal diseased tissue is poorly characterized. We observed that leucocytes infiltrating inflamed gingival tissue expressed marked levels of CX3CR1. In periodontal diseased tissue, the expression of fractalkine and CX3CR1 mRNA was detected by reverse transcription-polymerase chain reaction (RT-PCR) and further, fractalkine was distributed mainly on endothelial cells, as shown by immunohistochemistry. Moreover, we can detect CX3CR1-expressing cells infiltrated in periodontal diseased tissue by immunohistochemical staining. Furthermore, fractalkine production by human umbilical vein endothelial cells (HUVEC) was up-regulated by pathogen-associated molecular patterns (PAMPs), including Porphyromonas gingivalis lipopolysaccharide (LPS). Thus, these findings suggested that CX3CR1 and the corresponding chemokine, fractalkine may have an important regulatory role on specific leucocyte migration into inflamed periodontal tissue.

Involvement of IL-18 and soluble fas in patients with postoperative hepatic failure

We measured the levels of tumor necrosis factor alpha (TNF-alpha), interleukins (IL)-6 and -18, and soluble Fas (sFas) in 11 patients with postoperative hepatic failure and assessed whether IL-18-mediated apoptosis is involved in the onset of liver dysfunction. The serum TNF-alpha, IL-18, and sFas levels were significantly higher in patients with sepsis as a complication than in those without sepsis. The TNF-alpha and IL-18 levels were significantly higher in nonsurvivors than in survivors. Significant correlations were observed between TNF-alpha and IL-6, between TNF-alpha and IL-18, and between TNF-alpha and sFas levels. These results showed that Fas-mediated hepatocyte apoptosis functions as an important mechanism responsible for the onset of postoperative hepatic failure in humans. They especially suggested that IL-18 and TNF-alpha function both as apoptosis-promoting factors and as apoptosis-inhibiting factors, depending on the conditions to which hepatocytes are subjected.

Effectiveness of combining plasma exchange and continuous hemodiafiltration (combined modality therapy in a parallel circuit) in the treatment of patients with acute hepatic failure

Plasma exchange has gained widespread acceptance as an effective mode of blood purification in patients suffering from acute hepatic failure. However, it is still undetermined whether a single use of plasma exchange is capable of removing inflammatory cytokines completely or of preventing the development of citrate toxicity inherent with fresh frozen plasma. To clarify these issues we developed combined plasma exchange and continuous hemodiafiltration (CHDF) modality in which CHDF is performed in an opposite direction to plasma exchange. This study was designed to assess the effectiveness of combined modality therapy. Fifteen patients with acute hepatic failure were treated with plasma exchange (plasma exchange group) or plasma exchange and CHDF (plasma exchange + CHDF group), and various biochemical parameters were determined before and after treatment. Although citrate levels increased significantly after treatment compared with pretreatment levels in both the plasma exchange group and the plasma exchange + CHDF group, the percentage of the increase in citrate levels was significantly higher in the plasma exchange group than in the plasma exchange + CHDF group. Bilirubin levels were significantly lower after treatment in both the plasma exchange and plasma exchange + CHDF groups. There were no significant differences in tumor necrosis factor-alpha levels before and after treatment in the plasma exchange group, but they were significantly lower after treatment in the plasma exchange + CHDF group. Interleukin-6 (IL-6) levels increased significantly after treatment in the plasma exchange group, but there were no significant differences in the IL-6 levels before and after treatment in the plasma exchange + CHDF group. Interleukin-8 levels increased significantly after treatment in the plasma exchange group while decreasing significantly after treatment in the plasma exchange + CHDF group. These results indicate that combining plasma exchange and CHDF in a parallel circuit is an effective modality for suppressing the elevation of blood citrate levels and for removing inflammatory cytokines. This finding may have important implications for the development of an effective treatment for patients with acute hepatic failure.

Soluble products from Eikenella corrodens stimulate oral epithelial cells to induce inflammatory mediators

In the inflammatory response elicited by bacterial colonization in periodontal pockets, pocket epithelial cells not only serve as a barrier to isolate the pocket microenvironment from external stimuli but also regulate the functions of neighboring cells including fibroblasts and inflammatory cells. To elucidate this mechanism, we characterized the effects of periodontopathic bacterium Eikenella corrodens 1073 components on the production of some inflammatory mediators in a human oral epithelial cell line (KB). In enzyme-linked immunosorbent assay (ELISA), the E. corrodens supernatant induced interleukin-6 (IL-6), IL-8 and prostaglandin E2 but not interferon-gamma (IFN-gamma) production by KB cells. After incubation with E. corrodens supernatant, KB cells showed a marked increase in the levels of IL-6, IL-8 and PG G/H synthase (cyclooxygenase)-2, but not IFN-gamma, gene expression by reverse-transcriptase polymerase chain reaction. All these E. corrodens products responsible for production of these inflammatory mediators resisted freezing and boiling and were present in a 10-kDa filtrate. These results imply that these soluble small-molecular-mass products from E. corrodens stimulate various inflammatory mediator productions by human oral epithelial cells and may play a role in the initiation of periodontal inflammation and subsequently perpetuate the inflammatory response during chronic infection.

Involvement of soluble adhesion molecules in acute pancreatitis

The relationship between inflammatory cytokines and adhesion molecules in cases of acute pancreatitis was studied. Twenty-five patients were divided into three groups based on the severity of their disease as rated by the Ranson score. They were also divided into two groups according to the presence or absence of the complications of the multiorgan dysfunction syndrome (MODS) and the prognosis. As the severity of acute pancreatitis increased, the plasma levels of TNF-alpha, slCAM-1, sE-selectin, and sVCAM-1 also increased. The levels of all of these soluble adhesion molecules were significantly higher in the MODS-complicated group than in the non-MODS-complicated group. The levels of TNF-alpha, slCAM-1, and sVCAM-1 were significantly higher in patients who eventually died than in patients who survived. Significant correlations were observed between the levels of TNF-alpha and slCAM-1, between those of TNF-alpha and sVCAM-1, and between the levels of slCAM-1 and sVCAM-1. These results suggest that inflammatory cytokines stimulate the expression of adhesion molecules on the vascular endothelium and that mediators, including these adhesion molecules, are closely involved in the pathogenesis of acute pancreatitis. The plasma levels of these soluble adhesion molecules reliably reflected the severity of the disease.

Are proinflammatory cytokine concentrations reduced by plasma exchange in patients with severe acute hepatic failure?

We studied citric acid levels and proinflammatory cytokines (TNF-alpha, IL-6, and IL-8) before and after plasma exchange in 8 patients with acute liver failure. Plasma exchange was performed over a 6 to 7-hour period. At each session, 3.6 to 4.0 1 of plasma was exchanged for the same volume of fresh frozen plasma (FFP). The concentrations of citric acid were significantly increased after plasma exchange above concentrations before exchange (p<0.0001). There were no significant differences in TNF-alpha, IL-6, or IL-8 concentrations (p=0.7222, p=0.9357, p=0.6394, respectively). Thus, plasma exchange with FFP alone may not effectively remove cytokines.

Soluble Fas and soluble Fas ligand levels in patients with acute hepatic failure

PURPOSE

The Fas ligand (FasL)/Fas system is an apoptosis induction system that plays an important role in homeostasis and biophylaxis. We measured tumor necrosis factor alpha (TNF-alpha), soluble FasL (sFasL), and soluble Fas (sFas) in patients with acute hepatic failure to determine the relation between such failure and apoptosis.

MATERIALS AND METHODS

We assayed 21 blood samples from patients with acute hepatic failure and 8 from patients with sepsis but without acute hepatic failure. Serum TNF-alpha, sFas, and sFasL levels were determined by enzyme-linked immunosorbent assay.

RESULTS

sFasL levels were significantly higher in the patients with acute hepatic failure than in the patients with sepsis (0.68 +/- 0.42 ng/mL vs. 0 ng/mL, P =.0001). No significant differences were observed in sFas levels between the two groups. A significant correlation was observed between TNF-alpha and sFas levels (r = 0.657, P =.0008); a negative correlation was observed between TNF-alpha and sFasL levels (r = 0.454, P =.038).

CONCLUSIONS

Our results suggest that pathologic aggravation of acute hepatic failure are related to changes in the FasL/Fas system and that TNF-alpha and sFasL, in particular, may play hepatoprotective roles.

Failure to clear casts and secretions following inhalation injury can be dangerous: report of a case

A 27-year-old man suffered smoke inhalation during a fire. Three days later, he complained of respiratory difficulty and was admitted to our hospital. Bronchoscopy revealed a very large buildup of sputum mixed with soot extending from the left main bronchus to the bifurcation of the upper and lower lobe bronchi and causing both pulmonary atelectasis and pneumonia. The debris was successfully removed the next day with basket forceps via bronchoscopy. The patient's airway pressure dropped significantly, enabling extubation almost immediately. Because of the possibility for respiratory failure caused by viscous secretion, it is important to perform initial bronchoscopy in cases of suspected inhalation injury.

Nitrite/nitrate (NOx) levels and hemodynamics during septic shock

Nitric oxide (NO) acts as a vasorelaxant. We investigated the relationship between nitrite/nitrate (NOx), which are the final metabolites of NO, and hemodynamics during septic shock. We also examined tumor necrosis factor alpha (TNF-alpha), interleukin-8 (IL-8), and endotoxin. A significant negative correlation was observed between NOx levels and pulmonary capillary wedge pressure (PCWP; r = -0.6075, P = 0.0028). A significant positive correlation was noted between NOx levels and the cardiac index (CI; r = 0.5934, P = 0.0038). A significant negative correlation was found between NOx levels and the systemic vascular resistance index (SVRI; r = -0.4354, P = 0.0485). A significant positive correlation was observed between NOx levels and the stroke volume index (SVI; r = 0.5040, P = 0.0186). A significantly close positive correlation was also observed between TNF-alpha levels and NOx levels (r = 0.7848, P < 0.0001). These findings suggest that NOx levels are closely associated with hemodynamics during septic shock, resulting in a vascular relaxing effect.

Hyperemia of the intraperitoneal organs associated with scald burn

A 65-year-old man with a history of cerebral infarction sustained scald burns over 54% of the body surface. In spite of adequate fluid therapy, respiratory management with an artificial ventilator, and continuous hemodiafiltration, the patient died on day 5 post-admission. Autopsy revealed necrotic change on the surface of the liver, and necrosis and perforation of the ileum. Histologic examination showed necrosis of the hepatocytes lining the surface and necrosis of the hepatocytes and congestion in the central area of the liver. We speculated that systemic responses to the extensive burn resulted in hyperemia of the intraperitoneal organs, thereby inducing acute liver failure and the subsequent development of multiple organ failure.

Are nitrite/nitrate (NOx) levels elevated by inhalation injury?

The relationship between airway burn and nitric oxide (NO) levels in the early burn stage was investigated by quantifying nitrite/nitrate (NOx), which are the final metabolites of NO, in 22 burn patients. Although total body surface area (TBSA) and burn index (BI) were significantly higher in patients with airway-burn than in patients without airway burn (P=0.0347 and 0.0422, respectively), no significant difference in NOx levels was observed between the two groups (P=0.6196). The NOx levels were found to correlate significantly with TBSA (r=0.4775, P=0.0246). A significant correlation was also noted between the NOx levels and BI (r=0.4391, P=0.0409). These results suggest that NO reflects the intensity of inflammation in the early burn stage, but that excessive NO formation is unlikely to be induced by stress, such as that caused by airway burn.

Effectiveness of electrolyzed oxidized water irrigation in a burn-wound infection model

OBJECTIVE

The purpose of the study was to determine whether electrolyzed oxidized water (EOW) functions as a bactericide in burn injury with Pseudomonas aeruginosa infection in a rat burn-wound model.

METHODS

Anesthetized Sprague-Dawley rats (n = 31) were subjected to third-degree burns to 30% of total body surface area. Two days after injury, all rats were infected with P. aeruginosa using 1 mL of a suspension containing 1 x 10(8) colony-forming units. Rats were assigned to one of three groups: no irrigation (group I), irrigation with physiologic saline (group II), or irrigation with EOW (group III). Blood culture, endotoxin levels, and survival rates were determined.

RESULTS

Survival rate was significantly higher in group III than in groups I or II (p < 0.0001). Serum endotoxin levels on day 3 after infection in group III were significantly lower than the levels in group I (p < 0.01) and group II (p < 0.01). There were significant differences between the three groups in the culture of P. aeruginosa (p < 0.05).

CONCLUSION

Irrigation and disinfection with EOW may become useful in preventing burn-wound sepsis.

Electrolyzed strong acid aqueous solution irrigation promotes wound healing in a burn wound model

The purpose of the study was to understand the effectiveness of electrolyzed strong acid aqueous solution (ESAAS) for acceleration of epithelialization in a rat burn wound model. Eighteen anesthetized Sprague-Dawley rats received 30% total body surface area third-degree burns, and 2 days after injury, the wound eschars were removed. Rats were divided into 3 groups: Group 1, no irrigation; Group 2, irrigation with physiological saline; and Group 3, irrigation with ESAAS. Wounds were observed macroscopically until they were fully epithelialized, and epithelialized wounds were examined microscopically. Epithelialization of the wounds occurred significantly early in the rats treated with ESAAS (p < 0.05). Proliferation of associated lymphocytes and macrophages was more extensive in all rats that underwent irrigation than it was in control rats. ESAAS irrigation may promote tissue growth in burn wounds.

Long-term follow-up study of unruptured vertebral artery dissection: clinical outcomes and serial angiographic findings

OBJECT

Although the spontaneous occurrence of an unruptured vertebral artery (VA) dissection has increasingly been recognized as a relatively common cause of stroke, and the clinical aspects of this lesion have gradually been determined, its natural course remains obscure. The main goal of this study was to clarify the management protocol for this condition by examining serial angiographic changes in patients with unruptured VA dissections.

METHODS

Seventeen patients with unruptured VA dissections, including 13 men and four women, were clinically and angiographically examined between 1993 and 1998. All patients were observed using serial angiography studies. The initial angiography examinations most frequently revealed stenotic lesions (appearance of a pearl-and-string sign or string sign) in eight (47.1%) of 17 cases. In 15 cases (88.2%), changes in the lesions were evident on follow-up angiography studies. Stenotic lesions resulted in occlusion in four cases, normalization in three, and subsequent formation of an aneurysm in one case, which was treated successfully by proximal occlusion of the affected vessel performed using a detachable balloon. Occluded lesions, which were initially observed in three patients, recanalized in two patients and remained unchanged in one patient. Fusiform dilation alone was demonstrated in three patients during the initial angiography session; these lesions became normalized or were unchanged on follow-up studies. Saccular aneurysms were observed in two patients. In one of these cases, proximal ligation of the parent artery was successfully performed because of subsequent aneurysm enlargement. A double lumen, which appeared in one patient with an extradural VA dissection, became occluded. Magnetic resonance T2-weighted imaging studies revealed infarction corresponding to the posterior circulation in seven cases. During long-term observation in this series, good or excellent recovery was obtained in 14 (87.5%) of 16 patients, and moderate or severe disability in two (12.5%); one patient was lost to follow up after the second angiography study.

CONCLUSIONS

A follow-up angiography study must be performed during the early stage (within approximately 3 weeks after onset of symptoms) to confirm the formation or enlargement of an aneurysm, because such conditions may be amenable to surgical treatment. Unruptured VA dissection could otherwise be treated and followed conservatively. Although the majority of dissected lesions seem likely to stabilize within a few months, as evidenced on angiography, in some cases a longer observation period is required.

Red blood cells attenuate sinusoidal endothelial cell injury by scavenging xanthine oxidase-dependent hydrogen peroxide in hyperoxic perfused rat liver

AIMS/BACKGROUND

Rat liver perfused with an oxygenated buffered solution alone results in degenerative changes even when the perfusion flow is accelerated to give a sufficient oxygen supply. On the other hand, perfusion media supplemented with red blood cells (RBCs) preserve the viability of the liver. The present study was conducted to clarify how RBCs protect the isolated perfused liver.

METHODS

The liver was perfused with and without RBCs in a perfusate equilibrated with supra-physiological oxygen tension at regulated inflow pressures, and controlled hepatic oxygen consumption. We examined alanine aminotransferase and purine nucleoside phosphorylase activity in the perfusate as specific markers of liver cells injury. Hydrogen peroxide (H2O2) production and morphological changes were determined using cerium electron microscopy. Apoptosis was detected by measuring CPP 32 protease activity and using TdT-mediated dUTP-digoxigenin nick end-labeling.

RESULTS

When the liver was perfused with RBC-free buffer, H2O2 production and consequent injury progressing to apoptosis were initiated in the sinusoidal endothelial cells (SECs). After SECs were injured, H2O2 appeared in the hepatocytes. H2O2 production and associated degenerative changes were attenuated both morphologically and enzymatically by the addition of RBCs, a specific xanthine oxidase (XOD) inhibitor and the H2O2 radical scavenger, catalase.

CONCLUSIONS

In the liver perfused with RBC-free buffer, H2O2 production and consequent injury were initiated in SECs. RBCs attenuate liver injury by scavenging XOD-dependent H2O2.

Hydrogen peroxide induces midzonal heat shock protein 72 and apoptosis in sinusoidal endothelial cells of hypoxic rat liver

OBJECTIVE

To investigate the heat shock protein (HSP) 72 expression and apoptosis induced by hydrogen peroxide in hypoxic rat liver.

DESIGN

Prospective control study using the isolated rat liver.

SETTING

Animal research facility.

SUBJECTS

Fasted, pathogen-free specific, male Sprague-Dawley rats.

INTERVENTIONS

A low-flow hypoxia model was made by reducing an afferent pressure from 10 to 2.5 cm H2O, and by perfusing the isolated rat liver for 2 hrs.

MEASUREMENT AND MAIN RESULTS

We investigated the hydrogen peroxide production by using the 2'-7' dichlorofluorescein image, the induction of HSP 72 by using immunohistochemistry, and apoptosis by using terminal deoxynucleotidyl transferase-mediated dUTP-digoxigenin nick end-labeling method in the low flow hypoxic rat liver. In low-flow hypoxia, hydrogen peroxide production, HSP 72 expression, and apoptosis were induced in the midzone of rat liver. Prevalence of HSP 72 expression was higher in the sinusoidal endothelial cells (SEC) than in the hepatocytes. All apoptotic cells were SEC with expression of HSP 72. Hydrogen peroxide was derived from hepatocytes. Pretreatment with the specific xanthine oxidase inhibitor, sodium(-)-8-(3-methoxy-phenylsulfinylphenyl) pyrazolo [1,5-a]-1,3,5-triazine-4-olate monohydrate significantly attenuated hydrogen peroxide production, HSP 72 expression, and apoptosis of SEC in the midzone.

CONCLUSION

Xanthine oxidase-dependent hydrogen peroxide induces midzonal and SEC-dominant HSP 72 expression and apoptosis in hypoxic rat liver.

Tumor necrosis factor-alpha and tumor necrosis factor receptor I, II levels in patients with severe burns

Tumor necrosis factor alpha (TNF-alpha) and tumor necrosis factor receptor I and II (TNFRI and TNFRII) were studied in 24 burn patients who had a total burn surface area (TBSA) of 50.2 +/- 20.4%. Immediately after the injury, both the TNFRI and TNFRII levels correlated significantly with TBSA (r = 0.7344, P < 0.0001; r = 0.6074, P = 0.0012). The TNFRI and TNFRII levels immediately after the injury were significantly higher in the 11 patients who later died of their burns than in the 13 patients who survived (0.8 +/- 0.4 ng/ml vs. 1.8 +/- 0.7 ng/ml, P = 0.0002; 2.3 +/- 1.1 ng/ml vs. 4.5 +/- 1.6 ng/ml, P = 0.0009). The TNF-alpha levels immediately after the injury did not differ significantly between the group that survived and the group that died. The TNFRI and TNFRII values for the entire follow-up period also correlated significantly with TBSA. Peak TNFRI and TNFRII levels were significantly higher in the group that died than in the group that survived (6.0 +/- 4.7 ng/ml vs. 14.1 +/- 7.8 ng/ml, P = 0.0009; 7.0 +/- 5.1 ng/ml vs. 16.7 +/- 5.2 ng/ml, P = 0.0003). The TNF-alpha levels correlated significantly with both the TNFRI and the TNFRII levels. The TNFRI and TNFRII levels thus closely reflected the severity of the burns in both the acute postburn period and the subsequent follow-up period. In other words, these parameters well reflected the severity and outcome of the burns, irrespective of the presence or absence of accompanying infection.

Bound and soluble adhesion molecule and cytokine levels in patients with severe burns

We measured endotoxins, inflammatory cytokines and soluble adhesion molecules in the blood of 17 severe burn patients to determine the involvement of these factors in the pathophysiology of severe burns. All seventeen patients had burns with a total burn surface area of 20% or more and a burn index of 15% or more. Endotoxin was measured by an endotoxin-specific assay and tumor necrosis factor-alpha, interleukin 6 and interleukin 8 and soluble adhesion molecules were measured by enzyme-linked immunosorbent assay. CD11a, CD11b and CD18, measured by flow cytometry, were elevated in the non-surviving group, the septic shock group and the multiple organ dysfunction syndrome group, suggesting a close connection between these adhesion molecules and burns complicated by infection. Soluble adhesion molecules were found to indirectly reflect the level of endothelial cell adhesion molecules, suggesting that inflammatory cytokines may also be involved in their production.

Cardiac rupture by penetration of fractured sternum: a rare complication of cardiopulmonary resuscitation

We report an 82-year-old man in whom cardiopulmonary resuscitation (CPR) was unsuccessful. The postmortem examination revealed right atrial ruptures and pericardial sac perforation by a fractured sternal edge. Even though CPR-related cardiac rupture is rare, emergency medical staff should be aware of this complication.

Nuclear matrix protein levels in burn patients with multiple organ dysfunction syndrome

In this study, we investigated multiple organ dysfunction syndrome (MODS) and nuclear matrix protein (NMP), which is an indicator for apoptosis, in burn patients. The subjects were 17 patients with a total burn surface area (TBSA) of 26% or more. Eight of them had MODS, and nine did not. Seven patients died, and 10 survived. The NMP value in the group with MODS (610 +/- 318 units/ml) was significantly higher than in the group without MODS (82 +/- 31 units/ml). The NMP values of the patients who died (645 +/- 326 units/ml) were significantly higher than in the group who survived (111 +/- 95 units/ml), and they rose significantly as the number of impaired organs increased. Our findings suggested that the NMP level in burn cases associated with MODS was higher when apoptosis developed and larger numbers of organs were impaired.

The effective removal of proinflammatory cytokines by continuous hemofiltration with a polymethylmethacrylate membrane following severe burn injury: report of three cases

The serum levels of proinflammatory cytokines were investigated in three patients with severe burn injuries complicated by sepsis and pulmonary edema, who were treated with continuous hemofiltration (CHF) using a polymethylmethacrylate (PMMA) membrane. All patients had suffered burn injuries to more than 30% of their total body surface area (TBSA) and had burn indexes of 20 or more. Both interleukin (IL)-6 and tumor necrosis factor-alpha were detectable in one patient, while the serum IL-6 levels were elevated in the remaining two patients. The serum cytokines decreased 24 h after the initiation of CHF. Determinations of IL-6 in inflow and outflow blood samples as well as in the filtration fluid revealed that IL-6 was ultrafiltrated and/or adsorbed by the filter. Two of the three patients did not survive. Nevertheless, the results of this study indicate that since burn injuries are frequently associated with hypercytokinemia, the removal of cytokines by CHF with a PMMA membrane may be effective in the management of severe burn injuries.

Usefulness of procalcitonin in Pseudomonas burn wound sepsis model

Procalcitonin (PCT), a precursor of calcitonin, and endotoxin were determined in the burn wound sepsis model in which 21 Sprague-Dawley rats were scalded approximately 30% on their back. On day 2 post burn, the wounds were inoculated 1 x 10(8) colony-forming units of Pseudomonas aeruginosa. On day 5 post burn P. aeruginosa was detected by blood culture in 10 of the 21 rats (47.6%). The mortality rate 7 days after burn was 90.5%. Significant correlations were observed between serum endotoxin levels and serum PCT levels on day 5 post burn (r = 0.860, p<0.001). It was suggested that endotoxin may induce the release of PCT and that measuring the levels of PCT may be useful in diagnosing burn wound sepsis.

Interleukin-6 (IL-6) and IL-8 are induced in human oral epithelial cells in response to exposure to periodontopathic Eikenella corrodens

Periodontitis is the inflammatory response in periodontal tissues elicited by bacterial colonization in periodontal pockets. In this response, pocket epithelial cells are the first cells to come into contact with bacteria. To elucidate this mechanism, we determined the adherence of the periodontopathic bacterium Eikenella corrodens 1073, which has a GalNAc-sensitive lectin-like adhesin (EcLS), to a human oral epithelial carcinoma cell line (KB) and the induction of proinflammatory cytokine production in the cells following exposure to this bacterium in vitro. In the adherence assay, EcLS played a role as the adhesin of this bacterium in adherence to KB cells. In a reverse transcriptase PCR, significant interleukin-8 (IL-8) and IL-6 mRNA levels were induced in response to exposure to this bacterium. In an enzyme-linked immunosorbent assay after an 8-h bacterial exposure, the IL-8 and IL-6 protein levels were 13.5- and 8.3-fold higher than those in the nonexposed controls, respectively. These protein responses were time dependent. Interestingly, when E. corrodens was separated from KB cells by cell culture inserts, a slight stimulation of the IL-6 and IL-8 mRNA and secreted protein levels was seen. These results imply that the direct contact of E. corrodens 1073 with oral epithelial cells is not necessarily required for the stimulation of IL-6 and IL-8 secretion. We suggest that E. corrodens induces the epithelial cells to secrete proinflammatory cytokines which serve as an early signaling system to host immune and inflammatory cells in underlying connective tissues.

Plasma levels of type II phospholipase A2 and nitrite/nitrate in patients with burns

Type II phospholipase A2 (type II PLA2), nitrite/nitrate (NOx), tumor necrosis factor-alpha (TNF-alpha) and endotoxin were studied in burn patients. Type II PLA2 values and NOx values were both significantly higher in the group that died, the group with shock as a complication and the group with multiple organ dysfunction syndrome (MODS) as a complication, than in the group that survived, the group without shock as a complication and the group without MODS as a complication, respectively. The results suggested that type II PLA2 and nitric oxide (NO) may play a major role in the pathology of burn patients. Significant correlations were found between TNF-alpha and type II PLA2 values and between type II PLA2 and NOx values, suggesting the possibility of involvement in each other's production.

Functional characteristics and the complete primary structure of ascidian gelsolin

The body wall of the ascidian is composed of unusual multi-nucleated smooth muscle cells enriched with thin actin filaments containing troponin-tropomyosin which run along the longitudinal cell axis without being organized into striated structures. We purified an actin-binding protein of 80 kDa, tentatively termed 80K protein, from the body wall muscle of ascidian, Halocynthia roretzi, and characterized the functional properties and molecular structures. In the presence of Ca2+, the 80K protein accelerated the initial phase of actin polymerization, namely the nucleation process, decreased the level of polymerization at the steady state, caused marked reduction in viscosity of an F-actin solution, and fragmented F-actin filaments, while in the absence of Ca2+, it remained associated with F-actin without severing the filaments. The interaction of the 80K protein with actin was inhibited by phosphatidylinositol 4,5-bisphosphate (PIP2). When actin was polymerized in the presence of acrosome actin bundles from horseshoe crab sperm, the 80K protein inhibited the growth of actin filaments at the barbed end but not at the pointed end, indicating that the 80K protein functions as a barbed-end capping protein. In order to characterize the molecular structure of the 80K protein, cDNAs encoding this protein were isolated from the lambda gt11 cDNA library of the ascidian muscle by using a monoclonal antibody (AS23) specific for this protein and the entire sequence was determined. The deduced peptide sequence showed about 44% homology in amino acid residues with the human gelsolin sequence, and in addition, 6 repeating segments were observed in the sequence of the 80K protein as has been described in the gelsolin sequence. These results indicate strongly that the 80K protein belongs to the gelsolin family.

Developmentally regulated mRNA splicing of clathrin assembly protein 3 (AP-3)

Clathrin assembly protein 3 (AP-3) is a neuron-specific component of clathrin coated vesicles. Because it promotes the assembly of uniform clathrin cages, AP-3 may play a regulatory role in synaptic vesicle recycling. Previously, using the monoclonal antibody MabR-18, we demonstrated that AP-3 expression starts from the embryonic stage and is maintained at high levels from the early postnatal stages through adult. In order to study the expression of AP-3 during early postnatal development at the mRNA level, RT-PCR analysis was performed. We divided the coding region of AP-3 into 10 regions and designed primers to amplify each region. As a result, developmentally regulated splicing sites were found in two regions. In one region, a PCR product with a 108-bp deletion was detected from postnatal day 10 (P10). In the other region, a product with a 15-bp deletion was increased compensating for the decrease of the undeleted product. The expression of isoforms changed mainly from around P7 to P10, whereas the level of AP-3 protein remained relatively constant throughout postnatal development. These results suggest that the expression of AP-3 isoforms with mRNA splicing is developmentally regulated in the brain and may be involved in the maturation of synaptic vesicle recycling.

An immunohistochemical study on the localization of Porphyromonas gingivalis, Campylobacter rectus and Actinomyces viscosus in human periodontal pockets

The localization and distribution of Porphyromonas gingivalis, Campylobacter rectus and Actinomyces viscosus were studied in human periodontal pockets. After obtaining voluntary consent from 9 patients, 12 teeth and their surrounding periodontal tissue with advanced adult periodontitis were extracted carefully so as not to change the structure of the periodontal pockets. The specimens were processed into serial sections. One of the sections was stained with Brown & Brenn-modified Gram stain to observe the distribution of bacteria. The others were stained immunohistochemically by the Labelled Streptavidin Biotin method (LSAB method) using specific rabbit antibodies against selected bacteria. Some bacteria could be found within epithelial cells. P. gingivalis was found in 9/12 of the samples examined. Small aggregates of P. gingivalis were scattered in all parts of the periodontal pockets, and some of these aggregates could be seen in close contact with the epithelium. Conversely, C. rectus was observed in 5/12 of the samples examined and was predominantly located in the middle and deep pocket zones. C. rectus tended to form large clumps in both the tooth-attached and epithelium-associated plaque area. A. viscosus was observed in 7/12 of the samples examined and was localized predominantly in the tooth-attached plaque area, especially in the shallow and middle pocket zones. Although unexpected spills of unattached plaque from periodontal pockets was possible, immunohistochemical staining with species-specific antibodies was extremely sensitive and revealed the localization and the distribution of periodontal disease-associated bacteria in human periodontal pockets.