Loss of IκBζ Drives Dentin Formation via Altered H3K4me3 Status

Enforced enrichment of the active promoter marks trimethylation of histone H3 lysine 4 (H3K4me3) and acetylation of histone H3 lysine 27 (H3K27ac) by inhibiting histone demethylases and deacetylases is positively associated with hard tissue formation through the induction of osteo/odontogenic differentiation. However, the key endogenous epigenetic modulator of odontoblasts to regulate the expression of genes coding dentin extracellular matrix (ECM) proteins has not been identified. We focused on nuclear factor (NF)-κB inhibitor ζ (IκBζ), which was originally identified as the transcriptional regulator of NF-κB and recently regarded as the NF-κB-independent epigenetic modulator, and found that IκBζ null mice exhibit a thicker dentin width and narrower pulp chamber, with aged mice having more marked phenotypes. At 6 mo of age, dentin fluorescent labeling revealed significantly accelerated dentin synthesis in the incisors of IκBζ null mice. In the molars of IκBζ null mice, marked tertiary dentin formation adjacent to the pulp horn was observed. Mechanistically, the expression of COL1A2 and COL1A1 collagen genes increased more in the odontoblast-rich fraction of IκBζ null mice than in wild type in vivo, similar to human odontoblast-like cells transfected with small interfering RNA for IκBζ compared with cells transfected with control siRNA in vitro. Furthermore, the direct binding of IκBζ to the COL1A2 promoter suppressed COL1A2 expression and the local active chromatin status marked by H3K4me3. Based on whole-genome identification of H3K4me3 enrichment, ECM and ECM organization-related gene loci were selectively activated by the knockdown of IκBζ, which consistently resulted in the upregulation of these genes. Collectively, this study suggested that IκBζ is the key negative regulator of dentin formation in odontoblasts by inhibiting dentin ECM- and ECM organization-related gene expression through an altered local chromatin status marked by H3K4me3. Therefore, IκBζ is a potential target for epigenetically improving the clinical outcomes of dentin regeneration therapies such as pulp capping.

Wnt3a signaling induces murine dental follicle cells to differentiate into cementoblastic/osteoblastic cells via an osterix-dependent pathway

BACKGROUND AND OBJECTIVE

Dental follicle cells, putative progenitor cells for cementoblasts, osteoblasts and periodontal ligament cells, interplay with Hertwig's epithelial root sheath (HERS) cells during tooth root formation, in which HERS is considered to have an inductive role in initiating cementogenesis by epithelial-mesenchymal interaction. However, the specific mechanisms controlling the cementoblast/osteoblast differentiation of dental follicle cells are not fully understood. Canonical Wnt signaling has been implicated in increased bone formation by controlling mesenchymal stem cell or osteoblastic cell functions. This study examined the possible expression of canonical Wnt ligand in HERS and the role of Wnt signaling during the cementoblast/osteoblast differentiation of dental follicle cells.

MATERIAL AND METHODS

The expression of Wnt3a, a representative canonical Wnt ligand, in HERS was assessed by immunohistochemistry. The differentiation and function of immortalized murine dental follicle cells were evaluated by measuring alkaline phosphatase (ALP, Alpl) activity and osteogenic gene expression.

RESULTS

We identified the expression of Wnt3a in HERS during mouse tooth root development by immunohistochemistry as well as in cultured human epithelial rest cells of Malassez by real-time polymerase chain reaction, while no expression of Wnt3a was detected in cultured dental mesenchymal cells. Exposure of immortalized murine dental follicle cells to Wnt3a-induced ALP activity as well as expression of the Alpl gene. Pretreatment of cells with Dickkopf-1, a potent canonical Wnt antagonist, markedly attenuated the effect of Wnt3a on ALP expression. Furthermore, Wnt3a induced transcriptional activity of runt-related transcription factor 2 (Runx2) and expression of osterix at gene and/or protein levels. Treatment with osterix-small interfering RNA significantly inhibited Wnt3a-induced ALP expression at gene and protein levels.

CONCLUSION

These findings suggest that HERS has a potential role in stimulating cementoblast/osteoblast differentiation of dental follicle cells via the Wnt/β-catenin signaling pathway.

Triple/Single quantum filtered sodium MRI of acute brain ischemia

The effectiveness of reperfusion therapies during acute brain ischemia depends on the viability of the underperfused tissue. Specifically, when the ischemic tissue is viable reperfusion leads to improved clinical outcome. However, when the ischemic tissue is non-viable, reperfusion therapy can lead to intra-cerebral hemorrhage and/or an accelerated rate of ischemia formation. Perfusion and diffusion weighted proton MRI (DW MRI) are well-established techniques for the early detection of brain ischemia but are unable to positively establish the viability of the tissue. Tissue sodium concentration (TSC) has been shown to exhibit a linear and reversible response for many hours after ischemia onset. Because sodium accumulation in tissue is closely related to its metabolic status, we believe that the rate of TSC accumulation during evolving ischemia could provide useful information about tissue viability during evolving ischemia. In this paper, we discuss the technical details leading to the application of triple quantum (TQ) sodium MRI for the monitoring of brain ischemia. The proposed methods are then demonstrated in a non-human primate model of temporary middle cerebral artery (MCA) occlusion.

Expression of functional Toll-like receptors and nucleotide-binding oligomerization domain proteins in murine cementoblasts and their upregulation during cell differentiation

BACKGROUND AND OBJECTIVE

While the primary role of cementoblasts is to synthesize the components of cementum, we have reported that immortalized murine cementoblasts (OCCM-30) express functional Toll-like receptor (TLR)-2 and -4, and these receptors are involved in the alteration of gene expression associated with cementum formation and in the upregulation of osteoclastogenesis-associated molecules, such as receptor activator of nuclear factor-kappaB (NF-kappaB) ligand. We hypothesized that cementoblasts express a wide range of pattern recognition receptors in a manner comparable to osteoblasts, which are known to express various functional TLRs and nucleotide-binding oligomerization domain (NOD) proteins.

MATERIAL AND METHODS

Murine cementoblasts and pre-osteoblasts were used. The gene and protein levels of TLRs/NODs were analyzed using real-time polymerase chain reaction and flow cytometry. Interleukin-6 (IL-6) and activated NF-kappaB were measured using enzyme-linked immunosorbent assay.

RESULTS

The expressions of TLR-1, -2, -4, -6 and -9, CD14, NOD-1 and -2 were detected in cementoblasts and were upregulated upon differentiation induced by ascorbic acid. Similar patterns were observed in the mouse MC3T3-E1 osteoblast cell line. Synthetic ligands, Pam3CSK4 (TLR-1/2 agonist), Pam2CGDPKHPKSF (TLR-2/6 agonist), lipid A (TLR4 agonist), CpG DNA (TLR-9 agonist), FK565 (NOD1 agonist) and muramyldipeptide (NOD2 agonist), effectively induced NF-kappaB activation in cementoblasts and/or ascorbic acid-treated cementoblasts. Furthermore, these ligands induced IL-6 production in a NF-kappaB-dependent manner in cementoblasts and/or ascorbic acid-treated cementoblasts.

CONCLUSION

These results indicate that cementoblasts possess functional TLR and NOD signaling systems and have a similar capacity to osteoblasts in responding to a wide variety of pathogens.

Regulation of cementoblast function by P. gingivalis lipopolysaccharide via TLR2

Although cementoblasts express Toll-like receptors (TLR)-2 and -4, little is known regarding the possible participation of cementoblasts in the inflammatory response. We investigated the effects of Porphyromonas gingivalis lipopolysaccharide (LPS), tetra- and penta-acylated lipid A species (designated PgLPS(1435/1449) and PgLPS(1690), respectively), on gene expression of osteoclastogenesis-associated molecules in murine cementoblasts. Real-time quantitative RT-PCR analysis revealed that receptor activator of NF-kappaB ligand (RANKL), interleukin-6, Regulated on activation, normal T-cell expressed, and secreted (RANTES), macrophage inflammatory protein-1alpha, and monocyte chemoattractant protein-1 were rapidly and dramatically induced upon stimulation with PgLPS(1690), but only slightly induced with PgLPS(1435/1449). Osteoprotegerin, which was expressed constitutively, was not altered significantly. ELISA demonstrated synthesis of corresponding proteins. PgLPS(1690) significantly induced transcripts for NF-kappaB, and this activation was inhibited by pre-treatment with anti-TLR-2 but not with TLR-4 antibodies. These results suggest that cementoblasts participate in the recruitment of osteoclastic precursor cells by up-regulation of chemokines/cytokines.

Detailed images of asteroid 25143 Itokawa from Hayabusa

Rendezvous of the Japanese spacecraft Hayabusa with the near-Earth asteroid 25143 Itokawa took place during the interval September through November 2005. The onboard camera imaged the solid surface of this tiny asteroid (535 meters by 294 meters by 209 meters) with a spatial resolution of 70 centimeters per pixel, revealing diverse surface morphologies. Unlike previously explored asteroids, the surface of Itokawa reveals both rough and smooth terrains. Craters generally show unclear morphologies. Numerous boulders on Itokawa's surface suggest a rubble-pile structure.

Serial triple quantum sodium MRI during non-human primate focal brain ischemia

Triple quantum (TQ) sodium MRI techniques with clinically acceptable 18-min data acquisition times were demonstrated in vivo in a nonhuman primate model of focal brain ischemia. Focal brain ischemia was induced in four animals using embolization coils to occlude the posterior cerebral artery, and a balloon catheter to occlude the middle cerebral artery. A statistically significant increase (P < 0.001) in the TQ sodium MRI signal intensity in the ischemic hemisphere relative to the contralateral hemisphere was seen at all time points in all four animals. This increased TQ sodium MRI signal intensity was demonstrated as early as 0.6 hr after the onset of ischemia. The TQ sodium MRI hyperintensity corresponded to the anatomical location of the ischemic cortex, as indicated by the registration of the TQ imaging data with anatomical proton MRI data. The results demonstrate that early after the onset of ischemia, there was an increase in the TQ signal intensity in the ischemic hemisphere, and a negligible change in the single quantum (SQ) signal intensity.

Cleavage of PDGF receptor on periodontal ligament cells by elastase

Human leukocyte elastase, a neutrophil serine protease, is considered to be a potential immunoregulatory protease. Since the PDGF receptor (PDGFR) on periodontal ligament (PDL) cells is a crucial element for various functions, such as wound healing in periodontal tissue, we investigated the effect of elastase on the expression of PDGFR on PDL cells by flow cytometry and Western blotting. We found that PDGFR-alpha disappeared with an increasing dose of elastase, and PDGFR-beta was degraded into several fragments. Elastase degraded both receptors on fixed cells, indicating that the degradation resulted from direct proteolysis on the cell surface. Elastase also then disturbed the phosphorylation of ERK1/2, JNK/SARK, and p38, triggered by PDGF-AA and PDGF-BB, suggesting that elastase inhibited PDGFR-dependent cell activation in PDL cells. These results suggest that elastase may modulate the PDGF-mediated activity of PDL cells during periodontal wound healing.

E-PASS (The Estimation of Physiologic Ability and Surgical Stress) scoring system helps the prediction of postoperative morbidity and mortality in thoracic surgery

OBJECTIVE

When a new scoring system, 'E-PASS', standing for the Estimation of Physiologic Ability and Surgical Stress that predicts the postoperative surgical risk by quantification of the patient's reserve and surgical stress applied to a population of general thoracic surgery patients, it should be investigated if this system could help us or not.

METHODS

The comprehensive risk score (CRS) of the E-PASS and the clinical course were evaluated retrospectively in 282 consecutive patients with primary lung cancer (group A), and in 458 patients who underwent elective thoracic operations (group B).

RESULTS

The morbidity and mortality rates in both group A and group B increased as the CRS increased. The CRS correlated significantly with the morbidity score, length of stay and cost of hospitalization.

CONCLUSIONS

E-PASS scoring system may be useful in surgical decision-making and evaluating quality of care in patients who are tolerable for lung resection.

Proteolysis of ICAM-1 on human oral epithelial cells by gingipains

Cysteine proteinases (gingipains) from Porphyromonas gingivalis are considered key virulence factors of severe periodontitis and host immune evasion. Since expression of intercellular adhesion molecule-1 (ICAM-1) on gingival epithelium is indispensable in polymorphonuclear leukocyte (PMN) migration at the site of periodontitis, we examined the effects of gingipains on the expression of ICAM-1 on human oral epithelial cell lines (KB and HSC-2) by flow cytometry and Western blotting. We found that three purified forms of gingipains efficiently reduced ICAM-1 expression on the cells in a time- and dose-dependent manner. Gingipains reduced the expression on fixed cells and degraded the ICAM-1 in the cell membranes, indicating that the reduction resulted from direct proteolysis. They then disturbed the ICAM-1-dependent adhesion of PMNs to the cells. These results indicate that gingipains cleave ICAM-1 on oral epithelial cells, consequently disrupting PMN-oral epithelial cell interaction, and are involved in immune evasion by the bacterium in periodontal tissues.

An endovascular primate model for the production of a middle cerebral artery ischemic infarction

SUMMARY

An endovascular model for producing and studying middle cerebral artery acute ischemic strokes was developed to avoid the need for an open surgical approach to the middle cerebral, anterior cerebral, posterior cerebral and internal carotid arteries. Endovascular occlusion of these vessels followed by Xenon-CT cerebral blood flow study confirmed the production of a middle cerebral artery distribution infarct in two primates. The methodology, advantages and drawbacks of this model are discussed.

Cleavage of CD14 on human gingival fibroblasts cocultured with activated neutrophils is mediated by human leukocyte elastase resulting in down-regulation of lipopolysaccharide-induced IL-8 production

Activated polymorphonuclear leukocytes (PMNs) release various types of proteases and express them on the cell surface. The proteases play important roles in PMN-mediated events. In the present study, flow cytometric analysis revealed that CD14 expression on human gingival fibroblasts (HGF) was markedly reduced by PMA-activated PMNs in a coculture system. We found that this reduction was caused by both secreted and cell surface proteases produced by activated PMNs. A protease responsible for the reduction was found to be human leukocyte elastase (HLE) secreted from the activated PMNs by use of various protease inhibitors, although HLE was only partially involved in CD14 reduction caused by cell-bound molecule(s) on fixed PMNs. Analysis with purified HLE revealed a time- and dose-dependent reduction of CD14 on HGF, and complete reduction was observed by 20 microg/ml HLE treatment for 30-60 min, but the other molecules such as CD26, CD59, CD157, and MHC class I on HGF were only slightly reduced. This reduction of CD14 resulted from direct proteolysis by HLE on the cell surface, because HLE reduced CD14 on fixed HGF and also on purified cell membranes. As a result of CD14 proteolysis, IL-8 production by HGF was suppressed when triggered by 10 ng/ml LPS, but not by IL-1alpha, indicating that HLE inhibited a CD14-dependent cell activation. These findings suggested that activated PMNs have a potential negative feedback mechanism for HGF function at the inflammatory site, particularly in periodontal tissues.

[Effectiveness of docetaxel plus cisplatin in large cell lung cancer showing little response to prior chemotherapy with MVP]

The present patient was a 53-year-old male who had large cell lung cancer of c-T4N1M0. We administered multi-drug regimen including mitomycin C, vindesine and cisplatin (CDDP) because of cancer invasion into the great vessels seen on a chest CT. After 3 courses, the cancer showed no change in size. Therefore, we adopted chemotherapy of docetaxel (Taxotere: TXT) and CDDP. After 4 courses, the size of the mass had decreased (partial response). The only major toxic defect was grade 3 neutropenia. A good response to TXT and CDDP could lead to complete resection of lung cancer. It is suggested that TXT is effective in the treatment of large cell lung cancer.

Proteolysis of human monocyte CD14 by cysteine proteinases (gingipains) from Porphyromonas gingivalis leading to lipopolysaccharide hyporesponsiveness

Cysteine proteinases (gingipains) elaborated from Porphyromonas gingivalis exhibit enzymatic activities against a broad range of host proteins and are considered key virulence factors in the onset and development of adult periodontitis and host defense evasion. In this study, we examined the ability of arginine-specific gingipains (high molecular mass Arg-specific gingipain (HRGP) and Arg-specific gingipain 2) and lysine-specific gingipain (KGP) to cleave monocyte CD14, the main receptor for bacterial cell surface components such as LPS. Binding of anti-CD14 mAb MY4 to human monocytes was almost completely abolished by 0.3 microM HRGP and KGP treatments for 15 min, and 1 microM RGP2 for 30 min. In contrast, the expressions of Toll-like receptor 4, and CD18, CD54, CD59, and HLA-A, -B, -C on monocytes were slightly increased and decreased, respectively, by 0. 3 microM HRGP and KGP. This down-regulation resulted from direct proteolysis, because 1) gingipains eliminated MY4 binding even to fixed monocytes, and 2) CD14 fragments were detected in the extracellular medium by immunoblot analysis. Human rCD14 was degraded by all three gingipains, which confirmed that CD14 was a substrate for gingipains. TNF-alpha production by monocytes after HRGP and KGP treatments was decreased at 1 ng/ml, but not at 20 microg/ml LPS, indicating that gingipains inhibited a CD14-dependent cell activation. These results suggest that gingipains preferentially cleave monocyte CD14, resulting in attenuation of the cellular recognition of bacteria, and as a consequence sustain chronic inflammation.

Increase of CD26/dipeptidyl peptidase IV expression on human gingival fibroblasts upon stimulation with cytokines and bacterial components

CD26/dipeptidyl peptidase IV (DPPIV) is a cell surface ectoenzyme which participates in immune and inflammatory reactions. We found that CD26 was only partially expressed on human fibroblasts from periodontal tissues, whereas fibroblasts from lung and skin expressed CD26 constitutively as revealed by flow cytometry. We examined the possible upregulation of CD26 expression on human gingival fibroblasts in response to various stimulants. Interleukin-1alpha (IL-1alpha); tumor necrosis factor alpha; gamma interferon; lipopolysaccharide from Porphyromonas gingivalis, Prevotella intermedia, and Escherichia coli; and Prevotella glycoprotein augmented CD26 expression on gingival fibroblasts. Among the stimulants, IL-1alpha exhibited the most potent activity. Enzymatic activity of CD26 induced by IL-1alpha on fibroblasts was determined colorimetrically in terms of Gly-Pro hydrolysis of a synthetic chromogenic substrate, Gly-Pro p-nitroanilide. Among various inhibitors tested, diprotin A and phenylmethylsulfonyl fluoride inhibited the enzymatic activity, suggesting that the enzyme induced by IL-1alpha was DPPIV. The upregulation of CD26 mRNA expression upon stimulation with IL-1alpha was also revealed by a quantitative reverse transcription-PCR assay. In the kinetic experiment, 48 h and several days were required for maximum CD26 mRNA accumulation and CD26 molecule expression on the cell surface, respectively. The addition of cycloheximide at 2 h before IL-1alpha stimulation almost completely inhibited the accumulation of CD26 mRNA. These results suggested that induction of CD26 on human gingival fibroblasts is regulated at the transcriptional level and is also dependent on a de novo-synthesized protein factor(s).

Noninvasive continuous monitoring of cerebral oxygenation periictally using near-infrared spectroscopy: a preliminary report

PURPOSE

To report on the use of near-infrared spectroscopy (NIRS) to examine the changes in cerebral oxygenation in the periictal period in patients with seizures.

METHODS

Cerebral hemoglobin oxygen availability was monitored continuously and noninvasively with NIRS in three patients (one in the pediatric intensive care unit (ICU) and two in epilepsy-monitoring units) in conjunction with continuous EEG monitoring. Ictal events were recorded and compared with the pre-, intra-, and postictal periods for cerebral oxygen availability, as defined by oxygenated hemoglobin (HbO2), deoxygenated hemoglobin (Hb), and the redox state of cytochrome oxidase (cytox).

RESULTS

Several important preliminary observations were made by using this technology. First, a preictal increase in cerebral oxygenation began between 1 and 2 h and >10 h before the ictal event. Second, despite adequate perfusion, based on an observed increased HbO2, reduction in cytox indicates a perfusion-metabolism mismatch during seizure activity. Third, continued seizure activity and even isolated ictal events were associated with decreased cerebral oxygen availability. Fourth, differences in cerebral oxygen availability were noted between different types of seizures (e.g., electrographic seizures were accompanied by rapid reductions in HbO2 and cerebral blood volume without reduction of cytox, whereas electroclinical seizures were characterized by marked increases in HbO2 with or without reduction of cytox).

CONCLUSIONS

In this preliminary report on the use of NIRS for patients with seizures, we believe that NIRS allows continuous and noninvasive monitoring of changes in cerebral oxygenation periictally, thereby permitting investigations into the pathophysiology of seizures and the exploration of the potential of cerebral oximetry as a tool for seizure localization.

Noninvasive continuous monitoring of cerebral oxygenation periictally using near-infrared spectroscopy: a preliminary report

PURPOSE

To report on the use of near-infrared spectroscopy (NIRS) to examine the changes in cerebral oxygenation in the periictal period in patients with seizures.

METHODS

Cerebral hemoglobin oxygen availability was monitored continuously and noninvasively with NIRS in three patients (one in the pediatric intensive care unit (ICU) and two in epilepsy-monitoring units) in conjunction with continuous EEG monitoring. Ictal events were recorded and compared with the pre-, intra-, and postictal periods for cerebral oxygen availability, as defined by oxygenated hemoglobin (HbO2), deoxygenated hemoglobin (Hb), and the redox state of cytochrome oxidase (cytox).

RESULTS

Several important preliminary observations were made by using this technology. First, a preictal increase in cerebral oxygenation began between 1 and 2 h and >10 h before the ictal event. Second, despite adequate perfusion, based on an observed increased HbO2, reduction in cytox indicates a perfusion-metabolism mismatch during seizure activity. Third, continued seizure activity and even isolated ictal events were associated with decreased cerebral oxygen availability. Fourth, differences in cerebral oxygen availability were noted between different types of seizures (e.g., electrographic seizures were accompanied by rapid reductions in HbO2 and cerebral blood volume without reduction of cytox, whereas electroclinical seizures were characterized by marked increases in HbO2 with or without reduction of cytox).

CONCLUSIONS

In this preliminary report on the use of NIRS for patients with seizures, we believe that NIRS allows continuous and noninvasive monitoring of changes in cerebral oxygenation periictally, thereby permitting investigations into the pathophysiology of seizures and the exploration of the potential of cerebral oximetry as a tool for seizure localization.

[Preoperative evaluation of cardiac disease for patients with lung cancer: usefulness of treadmill exercise electrocardiogram]

118 patients with lung cancer who underwent treadmill exercise electrography (ECG) as part of their preoperative evaluation, were investigated for postoperative events. On the treadmill exercise ECG 27 patients were positive and 91 were negative. The more elderly patients tended to reveal ischemic findings in treadmill exercise ECG. Of the 71 patients with normal of result by ECG at rest, 15 patients (21.1%) had postoperative ischemic change on ECG. As a result, it was considered that this examination was insufficient to detect latent ischemic heart disease. The patients who had a discontinued at stage 2 or less of the Bruce protocol and had a negative result by treadmill exercise ECG, were classified as insufficient group and separated from the others. (27/118 patients). This group consisted of advanced age (p < 0.05) who tended to experience postoperative events. In the sufficient group, patients showed ischemic events predominantly on ECG at postoperative period (p < 0.01). We concluded that as preoperative screening of heart disease prior to lung cancer surgery ECG at rest was not adequate while treadmill exercise ECG was useful.

The use of near infrared spectroscopy (NIRS) in children after traumatic brain injury: a preliminary report

Children commonly develop diffuse cerebral swelling after traumatic brain injury (TBI) which is believed due to a secondary response to the injury. Near infrared spectroscopy (NIRS), a continuous, direct, and noninvasive monitor of cerebral oxygenation and cerebral blood volume (CBV), could be helpful in understanding these secondary responses. The aims of our study were to determine whether NIRS used in children with severe TBI will provide insight into the pathophysiology of injury. Ten children (1 mo to 15 years old) with severe TBI (admission GCS < or = 7) were continuously monitored by NIRS by placing optodes over the frontalparietal region. Relative values of oxyhemoglobin (HbO2), deoxyhemoglobin (Hb), and total hemoglobin (THb) were obtained and compared to intracranial pressure (ICP), mean arterial pressure (MAP), electroencephalography (EEG), and arterial PCO2 (PaCO2). Episodes of intracranial hypertension (ICP > 20 Torr [T]), changes in ICP > 10 T, changes in PaCO2 > or = 8 T, and changes in MAP > 20 T frequently resulted in changes in HbO2, Hb, and THb. Hyperventilation with decreased PaCO2 always resulted in cerebral oxygen desaturation irregardless of ICP. Often, high ICP correlated with increased THb and HbO2 indicating increased CBV and cerebrovascular dilatation. In two children, posttraumatic seizures were preceded by an unexplained rapid cerebral hyperoxygenation several hours prior to the onset of the clinical seizures. NIRS reliably detects changes in cerebral hemodynamics in children and may be used to further understand the etiology of the diffuse cerebral swelling seen in children after severe TBI.

Heterogeneous expression and release of CD14 by human gingival fibroblasts: characterization and CD14-mediated interleukin-8 secretion in response to lipopolysaccharide

To identify the role in periodontal inflammatory diseases of human gingival fibroblasts (HGF), the major constituents of gingival tissue, the expression of CD14, a possible lipopolysaccharide (LPS) receptor, and the release of soluble CD14 (sCD14) by HGF were examined. Among the HGF samples from the nine donors tested, more than 50% of the HGF from five donors expressed CD14 but less than 20% of HGF from the other four donors did so, as determined by flow cytometric analysis. The CD14 expression on the cell surface was correlated with the expression of CD14 mRNA. The HGF and skin and lung fibroblasts tested expressed no CD18, which indicates that fibroblasts do not possess other LPS receptors, such as CD11b/CD18 and CD11c/CD18. The CD14 expression by the HGF was decreased after subculturing and was highest at the confluent stage of culture. The treatment of high-CD14-expressing (CD14(high)) HGF with phosphatidylinositol-phospholipase C reduced CD14 expression; this result and the increase in a 55-kDa CD14 indicate that the membrane CD14 (mCD14) on the HGF may be a 55-kDa glycosylphosphatidylinositol-anchored protein. CD14(high) HGF spontaneously released 48- and 57-kDa sCD14. The total release of sCD14 by the HGF was augmented by gamma interferon and Escherichia coli LPS in accordance with the increased expression of mCD14. The CD14(high) HGF secreted interleukin-8 in response to LPS, and the secretion was completely inhibited by anti-CD14 antibody. These results suggest that (i) HGF consist of populations that are heterogeneous on the basis of different levels of expression of CD14 and (ii) CD14(high) HGF secrete inflammatory cytokines in response to LPS via CD14.

Circulating promyelocytes and low levels of CD16 expression on polymorphonuclear leukocytes accompany early-onset periodontitis

Early-onset periodontitis (EOP) is characterized by rapidly progressive alveolar bone loss, chemotactic defects of neutrophils, and significant familial aggregation. We found immature myeloid lineage cells, defined as promyelocytes, in the peripheral blood in patients with EOP. A hematological examination of peripheral blood cells showed normal reference values regarding cell proportions. Flow cytometry revealed significantly lower expression of CD16, a glycosylphosphatidylinositol (GPI)-anchored protein, on peripheral neutrophils in patients compared with those in age- and sex-matched healthy controls, whereas the levels of CD11a and CD11b expression were similar. The chemotactic response of neutrophils was lower toward not only formyl-methionyl-leucyl-phenylalanine but also complement fragment C5a than that of healthy controls. The expression of another GPI-anchored protein, CD14, was equally expressed by controls and patients. Therefore, the low level of CD16 expression was not due to the incomplete synthesis of the GPI anchor. GPI anchors of CD16 on neutrophils from controls and patients were both partially resistant to phosphatidylinositol-specific phospholipase C. The presence of promyelocytes in peripheral blood, low expression of CD16, and low chemotactic response of neutrophils suggest that patients with EOP have an abnormal maturation system in myeloid lineage cells in the bone marrow, which may be associated with the onset and course of EOP.

[Clinical evaluation on causes of death in patients with pulmonary tuberculosis who died within one year after diagnosing as TB]

We evaluated the cause of death in patients with pulmonary tuberculosis who died within one year after diagnosing as tuberculosis. Of 325 bacillary patients during the past seven years, 43 (13.2%) died within one year. Twenty-three patients (53.5%) died directly of tuberculosis. In this group, 13 patients died in emaciation state. Most of them were aged and under a poor nutritional condition. Some patients died in spite of improvement of tuberculosis. The fact indicates the need to detect tuberculosis as early as possible in elderly persons, and treatment should be initiated immediately. Eight patients died of respiratory failure and their chest X-ray film showed wade-spread tuberculosis. Seven of the patients died in spite of initiating treatment within one month after the onset of symptoms. This fact suggests the importance of regular check up by chest X-ray to detect tuberculosis early. Two patients died of massive hemoptysis. They had an episode of bloody sputum and the laboratory examination showed anemia. On the other hand, 20 patients died due to coexisting diseases unrelated to tuberculosis. Ten patients died of malignant diseases and most of them were lung cancer. Two patients died of hepatic failure possibly caused by the adverse reaction of TB chemotherapy. The interval between the onset of the treatment and death was less than a month, and the fact suggests the need to observe carefully for adverse reactions especially in the early stage of treatment.

Molecular cloning of a functional murine arginine-specific mono-ADP-ribosyltransferase and its expression in lymphoid cells

A protein mono-ADP-ribosyltransferase (ADPRT), anchored in the cell membrane as a glycosylphosphatidylinositol (GPI)-anchored cell-surface enzyme, was recently described on murine cytotoxic T cells (CTL). Expression of this enzyme was shown to exert regulatory functions on CTL proliferation and cytotoxic activity, presumably by modulating activity of the protein tyrosine kinase p56(lck), which is associated with the CTL co-receptor CD8. Here we report on the molecular cloning and expression of this important regulatory enzyme. The ADPRT coding sequence was derived by making use of ADPRT sequence homologies from different vertebrate species. A cDNA fragment of the enzyme coding sequence was generated by reverse transcription polymerase chain reaction (RT-PCR) from murine T-cell lymphoma SL12, which expresses the cell-surface ADPRT. The cDNA fragment was found to share extensive homology with the corresponding sequences of human and rabbit muscle ADPRT. In Northern blot hybridization, this cDNA fragment generates a strong hybridization signal with RNA from murine heart and skeletal muscle. Weak signals are seen with SL12, thymus, and spleen. Therefore, a murine skeletal muscle cDNA library was used to identify and obtain the coding sequence of the ADPRT gene. It is shown that the nucleic acid open reading frame sequence of the murine skeletal muscle gene shares 80.3% and 76.3% homology with the sequences of the human and rabbit muscle genes, respectively. Semiquantitative RT-PCR with intron-spanning primers shows that the ADPRT mRNA is present in lymphoid organs, cytotoxic T cells, and T-cell lines. Transfection of the ADPRT coding sequence into EL4 cells results in expression of the enzyme as a functional GPI-anchored cell-surface protein, able to ADP-ribosylate the arginine analog agmatine as well as cell-surface molecules.

[A case of acquired immunodeficiency syndrome with disseminated Mycobacterium avium complex infection in which M. avium was isolated from bone marrow]

A 46-year old man was admitted to a hospital because of cough and dyspnea. He was diagnosed as interstitial pneumonia and was treated with prednisolone (PSL) and antibiotics. The symptoms improved temporarily but he soon developed acute respiratory failure and was transferred to our hospital. Chest X-ray and CT revealed ground-glass opacities in both lung fields. He was treated with methyl PSL, antibiotics, and antimycobacterial drugs but he died on the fourth hospital day. Retrospectively, hematologic laboratory examinations revealed that CD4+ cell count was 0/microliter and serological tests for HIV were positive by both EIA and Western blot methods. The culture of the bone marrow specimens was positive for mycobacteria other than M. tuberculosis, and the bacilli were identified as Mycobacterium avium. Thus, his disease was eventually diagnosed as disseminated Mycobacterium avium complex (MAC) infection. In the past reports, the diagnosis of disseminated MAC infection was most often made by blood cultures, however, the isolation of MAC from bone marrow is another sensitive and specific method for the diagnosis of this infection. In some cases, bone marrow examination would be useful to diagnose disseminated MAC infection.

Regulation of cytotoxic T cell functions by a GPI-anchored ecto-ADP-ribosyltransferase

Protein mono-(ADP-ribosyl)transferases (ADPRTs) catalyze transfer of the ADP-ribose moiety from nicotinamide adenine dinucleotide (NAD) to specific amino acids. We recently described presence of an enzyme with this activity on cytotoxic T cells (CTL). Incubation of CTL with micromolar concentrations of NAD causes inhibition of cell proliferation and cytolytic activity. ADPRT can be released by bacterial phosphoinosital specific phospholipase C, indicating that it is a glycosylphosphatidylinositol (GPI) anchored exo-enzyme. Enzymatic release of ADPRT results in inability of NAD to modulate CTL function. Expression of ADPRT was found to be regulated, in quiescent CTL ADPRT is expressed at significant levels, however, upon TCR crosslinking it is rapidly released by an anchor hydrolyzing mechanism. This results in relative insensitivity to the inhibitory action of NAD. The question how ADPRT regulates T cell functions was investigated by incubating CTL with radioactively labeled NAD which causes modification of several proteins, pointing to potential candidates in these regulatory processes. We found that the protein tyrosine kinase p56lck but not p59fyn exists in a digitonin resistant complex with a 40 kD protein, which in its ADP-ribosylated form suppresses p56lck kinase activity. ADP-ribosylation of this protein is mediated by the arginine specific protein mono-ADPRT, presumably utilizing ecto-NAD as substrate. Release of the ADPRT by GPI-specific phospholipase C results in failure of ecto-NAD to downmodulate p56lk kinase activity. Concomitant to suppression of the kinase by ecto-NAD, CD8 mediated transmembrane signaling is found to be inhibited, whereas transmembrane signaling via CD3 is only slightly affected.

Cell surface ADP-ribosyltransferase regulates lymphocyte function-associated molecule-1 (LFA-1) function in T cells

Post-translational modifications are important in regulating the functions of signal proteins. This is well established for intracellular proteins, but little is known in the case of extracellular domains of cell surface molecules. We recently described a cell surface protein, mono-ADP-ribosyltransferase (ADPRT), on cytotoxic T cells and showed that it mediates attachment of ADP-ribose to cell surface proteins. Concomitantly, cytolytic activity and cell proliferation are inhibited. Here we report that one of the principal proteins modified by this enzyme is lymphocyte function-associated molecule-1 (LFA-1). While both chains are ADP-ribosylated on the extracellular domain of the molecule, persistence of the modification differs between the chains. Label is released from the beta-chain by 1 h, yet remains for at least 6 h on the alpha-chain. Loss of label is suppressed by phosphodiesterase inhibitors such as ADP-ribose and p-nitrophenylthymidine 5'-monophosphate, pointing to the involvement of this class of enzyme. Modification of LFA-1 requires expression of the cell surface ADPRT and causes the loss of epitopes recognized by alpha- and beta-chain-specific Abs. Concomitantly, the generation of inositol phosphates induced by Ab cross-linking of LFA-1 is significantly inhibited. Consistent with this effect, anti-LFA-1-induced homotypic cell adhesion is also inhibited. These effects are not seen in cells from which the ADPRT was removed by phospholipase C. Moreover, cells lacking the cell surface ADPRT are not inhibited by NAD in the cell adhesion assay, but gain this property upon transfection with the ADPRT gene. It is concluded that the cell surface protein mono-ADPRT regulates LFA-1 functions.

Cell surface ADP-ribosyltransferase regulates lymphocyte function-associated molecule-1 (LFA-1) function in T cells

Post-translational modifications are important in regulating the functions of signal proteins. This is well established for intracellular proteins, but little is known in the case of extracellular domains of cell surface molecules. We recently described a cell surface protein, mono-ADP-ribosyltransferase (ADPRT), on cytotoxic T cells and showed that it mediates attachment of ADP-ribose to cell surface proteins. Concomitantly, cytolytic activity and cell proliferation are inhibited. Here we report that one of the principal proteins modified by this enzyme is lymphocyte function-associated molecule-1 (LFA-1). While both chains are ADP-ribosylated on the extracellular domain of the molecule, persistence of the modification differs between the chains. Label is released from the beta-chain by 1 h, yet remains for at least 6 h on the alpha-chain. Loss of label is suppressed by phosphodiesterase inhibitors such as ADP-ribose and p-nitrophenylthymidine 5'-monophosphate, pointing to the involvement of this class of enzyme. Modification of LFA-1 requires expression of the cell surface ADPRT and causes the loss of epitopes recognized by alpha- and beta-chain-specific Abs. Concomitantly, the generation of inositol phosphates induced by Ab cross-linking of LFA-1 is significantly inhibited. Consistent with this effect, anti-LFA-1-induced homotypic cell adhesion is also inhibited. These effects are not seen in cells from which the ADPRT was removed by phospholipase C. Moreover, cells lacking the cell surface ADPRT are not inhibited by NAD in the cell adhesion assay, but gain this property upon transfection with the ADPRT gene. It is concluded that the cell surface protein mono-ADPRT regulates LFA-1 functions.

Isolation of a new superantigen with potent mitogenic activity to murine T cells from Streptococcus pyogenes

A mitogenic substance on murine lymphocytes was detected in the culture supernate of Streptococcus pyogenes type 12 strain. This substance had a molecular weight of 28,000 and pI 9.2, and was designated as S. pyogenes mitogen (SPM). The proliferative response of C3H/HeN spleen cells began at 1 ng ml-1 and reached a maximal response at 100 ng ml-1 of SPM for 4 days culture. Anti-Thy 1.2 mAb and complement-treated spleen cells abrogated the proliferative response to any dose of SPM. Although the anti-major histocompatibility complex class 1 mAbs had no blocking effect on proliferation by SPM, this proliferation was substantially inhibited by the addition of either anti-I-A or anti-I-E mAb, and complete inhibition was produced by the addition of both mAbs. Fixed antigen-presenting cells still induced T cell proliferation by SPM. A significant expansion of T cells bearing V beta 13 T-cell receptor was observed up to 73% among the Thy 1.2+ cells in cultures stimulated with SPM, indicating expansion in a V beta-specific manner. Immunoblotting of IEF-separated proteins showed that anti-streptococcal pyrogenic exotoxin (SPE) C reacted with a protein of pI 6.9 and anti-SPEB did not show any reactivity. SPEA was reported to expand V beta 8.1 and 8.2 bearing murine T cells, and SPM did not. SPM also exhibited potent mitogenic activity on human T cells and V beta 21+ T cells were selectively expanded. These results lead to the conclusion that SPM was neither SPEA, B nor C, but a new protein belonging to a group of streptococcal superantigens with activity on not only human but also murine lymphocytes.

Regulation of CTL by ecto-nictinamide adenine dinucleotide (NAD) involves ADP-ribosylation of a p56lck-associated protein

Receptor-mediated activation of T lymphocytes involves protein phosphorylation by several protein tyrosine kinases, among those the src-related enzymes p56lck and p59fyn. Accumulating evidence supports the notion that these enzymes are regulated by tyrosine phosphorylation and dephosphorylation, but much is yet to be learned about regulation of their activity. Here we demonstrate that p56lck but not p59fyn exists as a complex with a 40-kDa protein, which in its ADP-ribosylated form inhibits p56lck kinase activity. ADP-ribosylation of this protein is mediated by an arginine-specific mono-ADP-ribosyltransferase, which makes use of extracellular nicotinamide adenine dinucleotide (NAD). This enzyme is a glycosyl-phosphatidylinositol-anchored protein releasable from the surface of cytotoxic T cells by glycosyl-phosphatidylinositol-specific phospholipase C. Release of arginine-specific mono-ADP-ribosyltransferase results in failure of extracellular NAD to downmodulate p56lck kinase activity. Concomitant to suppression of the kinase by NAD, CD8 mediated transmembrane signaling and p56lck kinase activation are inhibited.

Regulation of CTL by ecto-nictinamide adenine dinucleotide (NAD) involves ADP-ribosylation of a p56lck-associated protein

Receptor-mediated activation of T lymphocytes involves protein phosphorylation by several protein tyrosine kinases, among those the src-related enzymes p56lck and p59fyn. Accumulating evidence supports the notion that these enzymes are regulated by tyrosine phosphorylation and dephosphorylation, but much is yet to be learned about regulation of their activity. Here we demonstrate that p56lck but not p59fyn exists as a complex with a 40-kDa protein, which in its ADP-ribosylated form inhibits p56lck kinase activity. ADP-ribosylation of this protein is mediated by an arginine-specific mono-ADP-ribosyltransferase, which makes use of extracellular nicotinamide adenine dinucleotide (NAD). This enzyme is a glycosyl-phosphatidylinositol-anchored protein releasable from the surface of cytotoxic T cells by glycosyl-phosphatidylinositol-specific phospholipase C. Release of arginine-specific mono-ADP-ribosyltransferase results in failure of extracellular NAD to downmodulate p56lck kinase activity. Concomitant to suppression of the kinase by NAD, CD8 mediated transmembrane signaling and p56lck kinase activation are inhibited.

Release of a glycosylphosphatidylinositol-anchored ADP-ribosyltransferase from cytotoxic T cells upon activation

Many cell surface proteins are anchored into the cell membrane by glycosylphosphatidylinositol (GPI), among those a recently discovered arginine-specific mono-ADP-ribosyltransferase on cytotoxic T cells (CTL). This enzyme transfers ADP-ribose to cell surface proteins resulting in inhibition of cytotoxic and proliferative activity. Here we report that ADP-ribosyltransferase is released in active forms by crosslinking CD3, exposure to Il-2 or PMA stimulation. Release of transferase is specific, as another GPI-anchored protein, Thy-1 is not released. Transferase molecules released by cell activation are indistinguishable in size from molecules released by phospholipase C, suggesting that the release mechanism acts close to or within the GPI anchor. Protease inhibitors fail to inhibit transferase release with exception of 1,10-phenanthroline and its 4,7-diphenyl derivative. This suggests that the release mechanism acts on the cell surface but does not discriminate between action of a metalloprotease or phospholipase D. Release of transferase is shown to be rapid, it is not suppressed by monensin or brefeldin A and independent of serum phospholipase D, consistent with a mechanism acting on the cell surface. Transferase expression is shown to be dependent on the cell activation stage. In CTL clones, the transferase is demonstrable as a phospholipase C releasable molecule at early but not later stages of Ag specific activation.

Release of a glycosylphosphatidylinositol-anchored ADP-ribosyltransferase from cytotoxic T cells upon activation

Many cell surface proteins are anchored into the cell membrane by glycosylphosphatidylinositol (GPI), among those a recently discovered arginine-specific mono-ADP-ribosyltransferase on cytotoxic T cells (CTL). This enzyme transfers ADP-ribose to cell surface proteins resulting in inhibition of cytotoxic and proliferative activity. Here we report that ADP-ribosyltransferase is released in active forms by crosslinking CD3, exposure to Il-2 or PMA stimulation. Release of transferase is specific, as another GPI-anchored protein, Thy-1 is not released. Transferase molecules released by cell activation are indistinguishable in size from molecules released by phospholipase C, suggesting that the release mechanism acts close to or within the GPI anchor. Protease inhibitors fail to inhibit transferase release with exception of 1,10-phenanthroline and its 4,7-diphenyl derivative. This suggests that the release mechanism acts on the cell surface but does not discriminate between action of a metalloprotease or phospholipase D. Release of transferase is shown to be rapid, it is not suppressed by monensin or brefeldin A and independent of serum phospholipase D, consistent with a mechanism acting on the cell surface. Transferase expression is shown to be dependent on the cell activation stage. In CTL clones, the transferase is demonstrable as a phospholipase C releasable molecule at early but not later stages of Ag specific activation.

Primary pulmonary lymphoma: relationship between clinical features and pathologic findings in 24 cases. The Japan National Chest Hospital Study Group for Lung Cancer

To elucidate the relationship between the clinical features and pathologic findings of primary pulmonary lymphoma, we reviewed 24 patients with this disease. The pulmonary lymphomas were divided into four groups: (1) B-cell lymphoma composed of small to medium-sized lymphoid cells (19 cases); (2) B-cell lymphoma composed of large lymphoid cells (three cases); (3) T-cell lymphoma (one case); (4) malignant lymphoma of lymphomatoid granulomatosis (LYG) type (one case). Radiographs of the first group revealed a predominance of infiltration associated with ill-defined tumor margins upon gross pathology, corresponding histologically to lymphangitic spread. Air bronchogram and pleural tail or abutment were additional radiographic features. Characteristics of the second group were a nodule or mass evident on radiographs and well-circumscribed tumor margins upon gross pathology. Lack of air bronchogram was an another radiographic feature in this group. Seventeen patients in these two groups underwent complete resection of the tumors and survived without recurrence, whereas four received chemotherapy after biopsy and survived with disease. These results indicate that primary pulmonary B-cell lymphoma is a low-grade malignancy and that complete resection is the only therapy which leads to cure. In a single patient with T-cell lymphoma, the radiographic and pathologic features of the tumor were indistinguishable from those in the first group, but the patient had an unfavorable prognosis. We consider that, from a prognostic viewpoint, it is important to determine the T- or B-immunophenotype of the tumor cells for diagnosis of primary pulmonary lymphoma. The only patient in this series with pulmonary lymphoma of LYG type showed distinctive clinicopathologic findings. We consider that this uncommon disease should be separated from other types of primary pulmonary lymphoma.

Regulation of cytotoxic T cells by ecto-nicotinamide adenine dinucleotide (NAD) correlates with cell surface GPI-anchored/arginine ADP-ribosyltransferase

This report demonstrates that incubation of cytotoxic T cells with NAD causes suppression of their ability to proliferate in response to stimulator cells or to lyse targets. Effects are evident after incubation for 3 h with concentrations of NAD as low as 1 microM and are sustained for many hours after removal of NAD from culture media. Suppression is a result of the failure of CTL to form specific conjugates with targets as well as a lower level of activation in response to TCR-mediated stimulation, although TCR-mediated transmembrane signaling is demonstrable. Metabolites of NAD such as nicotinamide, ADP-ribose, and cyclic-ADP-ribose have no detectable effect, indicating that NAD-glycohydrolase or ADP-ribose cyclase do not mediate suppression. Incubation of intact CTL with [32P]NAD leads to incorporation of 32P into a particulate, subcellular fraction, a reaction that is not inhibitable by ADP-ribose. Hydroxylamine, but not mercuric ion releases [32P]ADP-ribose, whereas phosphodiesterase releases [32P]AMP from the particulate subcellular fraction, suggesting that labeling is a result of enzymatic mono-ADP-ribosylation of arginines. In support of this, treatment of intact CTL with phosphatidylinositol-specific phospholipase C releases an arginine-specific ADP-ribosyltransferase and causes insensitivity to ecto-NAD suppression. These results suggest that a GPI-anchored ADP-ribosyltransferase uses ecto-NAD to ADP-ribosylate proteins that regulate CTL function.

Regulation of cytotoxic T cells by ecto-nicotinamide adenine dinucleotide (NAD) correlates with cell surface GPI-anchored/arginine ADP-ribosyltransferase

This report demonstrates that incubation of cytotoxic T cells with NAD causes suppression of their ability to proliferate in response to stimulator cells or to lyse targets. Effects are evident after incubation for 3 h with concentrations of NAD as low as 1 microM and are sustained for many hours after removal of NAD from culture media. Suppression is a result of the failure of CTL to form specific conjugates with targets as well as a lower level of activation in response to TCR-mediated stimulation, although TCR-mediated transmembrane signaling is demonstrable. Metabolites of NAD such as nicotinamide, ADP-ribose, and cyclic-ADP-ribose have no detectable effect, indicating that NAD-glycohydrolase or ADP-ribose cyclase do not mediate suppression. Incubation of intact CTL with [32P]NAD leads to incorporation of 32P into a particulate, subcellular fraction, a reaction that is not inhibitable by ADP-ribose. Hydroxylamine, but not mercuric ion releases [32P]ADP-ribose, whereas phosphodiesterase releases [32P]AMP from the particulate subcellular fraction, suggesting that labeling is a result of enzymatic mono-ADP-ribosylation of arginines. In support of this, treatment of intact CTL with phosphatidylinositol-specific phospholipase C releases an arginine-specific ADP-ribosyltransferase and causes insensitivity to ecto-NAD suppression. These results suggest that a GPI-anchored ADP-ribosyltransferase uses ecto-NAD to ADP-ribosylate proteins that regulate CTL function.

Substantia nigra damage after fluorothyl-induced seizures in rats worsens after post-seizure recovery: no exacerbation with hyperglycaemia

The substantia nigra pars reticularis (SNPR) of rats is highly susceptible to both seizure- and ischaemia-mediated damage. Hyperglycaemic exacerbation of brain damage similar to that observed after global brain ischaemia may also occur in rats with status epilepticus. We tested the hypotheses that hyperglycaemia exacerbates seizure-induced SNPR damage in rats and that SNPR lesions develop rapidly post-seizure. Halothane-anaesthetized, paralysed, and mechanically ventilated rats were prepared for haemodynamic and EEG monitoring. Halothane was discontinued, and mechanical ventilation on 30% oxygen/70% nitrous oxide was continued for 1 h. Three treatment groups (20 rats each) were studied: (1) control, lactated Ringer's solution; (2) equiosmolar control, 40% mannitol; and (3) hyperglycaemia, 50% dextrose. Infusions were started 5 min before seizures were induced with flurothyl 3% administered for either 45 (n = 10) or 75 (n = 10) min. Immediately after seizures, half of the animals underwent cerebral perfusion-fixation with formalin and half were allowed to recover for 2 h post-seizure and then perfused. Brain histology was assessed by light microscopy and scored 0-5 (0 = no damage) for the percentage of eosinophilic neurons and vacuolation in the SNPR. Glucose administration decreased the severity of SNPR damage in rats subjected to 75 min of seizures and 2 h recovery (pathology scores: control, eosinophilic neurons = 3.6, vacuolation = 4.0; hyperglycaemia, eosinophilic neurons = 3.0, vacuolation = 2.75; p < 0.05). SNPR damage was worse after 2 h of recovery (pathology scores: 0 h recovery, eosinophilic neurons = 0.9, vacuolation = 0.1; 2 h recovery, eosinophilic neurons = 3.9, vacuolation = 3.8; p < 0.05).(ABSTRACT TRUNCATED AT 250 WORDS)

Elevated production of interleukin 6 by hepatic MNC correlates with ICAM-1 expression on the hepatic sinusoidal endothelial cells in autoimmune MRL/lpr mice

MRL/lpr mice, which are a model of SLE and rheumatoid arthritis in humans, develop profound lymphadenopathy resulting from the accumulation of CD3+ 4-8- double-negative (DN) alpha beta T cells in peripheral lymphoid tissues. We previously indicated that these DN alpha beta T cells preferentially proliferate in the liver and migrate to the periphery. In this study, we analyzed whether any kind of cytokine was produced by hepatic mononuclear cells (MNC) in MRL/lpr mice. The evidence obtained indicates that interleukin 6 (IL-6) was vigorously produced by hepatic MNC in diseased MRL/lpr mice under unstimulated conditions. MNC in the spleen of these mice produced small amounts of IL-6, while those in the lymph nodes did not produce any appreciable amounts of IL-6. These activities of hepatic MNC in diseased MRL/lpr mice were almost completely neutralized by anti-mouse IL-6 monoclonal antibody (mAb). On the other hand, immunohistochemical staining of light- and electron-microscopic analyses revealed that the intracellular cell adhesion molecule 1 (ICAM-1) was expressed on the hepatic sinusoidal endothelial cells of diseased MRL/lpr mice. Moreover, ICAM-1 was newly induced in the hepatic sinusoids of control C3H/He mice by an intravenous injection of 50 units of recombinant mouse IL-6. These data suggest that ICAM-1 expressed on the hepatic sinusoidal endothelial cells in MRL/lpr mice is induced by IL-6, which is produced by hepatic MNC, and that such ICAM-1 may be responsible for the saturation of inflammatory cells and the proliferation of lymphocytes in the liver of MRL/lpr mice.

[Thallium-201 and gallium-67 scintigraphies in the diagnosis of pneumoconiosis combined with lung cancer]

Thallium-201 (201Tl) and Gallium-67 (67Ga) scintigraphies were performed on 62-year-old male with silicosis combined with lung cancer (squamous cell carcinoma). In 67Ga and early 201Tl images, radiotracer uptakes were observed in both sites of cancer and silicosis, and thus, it was impossible to differentiate cancer mass from the large opacity of pneumoconiosis. On the other hand, in the 201Tl delayed images, 201Tl was localized only in cancer mass, while it was washed out from the large opacity. Our findings indicated that 201Tl early and delayed scintigraphy findings were very useful to differentiate lung cancer from silicosis.

Brain glutamine synthetase activity and hyperoxia in neonatal rats

We have previously shown that exposure to 100% oxygen for 2 h results in a two-fold decrease in the brain glutamine synthetase activity of neonatal rats. The present study examines whether this decrement in enzyme activity leads to a global accumulation of glutamate, an excitotoxin which is a substrate for this enzyme. Despite a demonstrable decrement in whole brain glutamine synthetase activity, whole brain glutamate content is unaltered in animals exposed to 100% oxygen for 2 h. Furthermore, despite a persistent two-fold decrement in glutamine synthetase activity in animals exposed to 100% oxygen for 6 h, there remained no significant difference in glutamate content or in the glutamate/glutamine ratio between these animals and animals similarly exposed to room air. These results imply that the observed decrease in glutamine synthetase activity does not globally influence the glutamate content of the brain.

Blood flow and electrolytes in spinal cord ischemia

The contribution of reoxygenation-reperfusion injury to ischemic brain damage has been clearly demonstrated but not in the spinal cord. To evaluate this phenomenon in spinal cord ischemia, we measured spinal cord blood flow (SCBF) by [14C]iodoantipyrine and electrolytes in rabbits after 10 or 40 min ischemia followed by 30 min or 4 days recirculation. Ischemia for 10 or 40 min reduced blood flow in the lower lumbar segments L5-L7 (30 ml/100 g/min) to 5 and 10% of control. After 30 min of recirculation moderate hyperemia (25-40% above control) was observed in segments L5-L7 which was not related to the degree of functional impairment. Na+, water, and Ca2+ increased and K+ decreased after 40 min ischemia, but were unchanged after 10 min ischemia. Recirculation for 30 min after 40 min of ischemia resulted in a progressive rise in Ca2+ which correlated with irreversible spinal cord injury.

Platelet-activating factor antagonists do not attenuate delayed posttraumatic cerebral edema in rats

Platelet-activating factor (PAF) receptor antagonists reportedly improve early postischemic neurological recovery and cerebral blood flow in selected experimental models. Their effects on posttraumatic cerebral edema have, however, not been examined. In a rat model of right hemispheric percussive cerebral trauma, we examined the effects of two PAF receptor antagonists on posttraumatic edema formation. Two groups of rats received either BN 52021 (n = 14) or WEB 2086 (n = 11), 10 mg/kg i.v. at 15 min posttrauma. Two other groups treated with the BN 52021 (n = 17) and WEB 2086 (n = 10) vehicles served as controls. Hemispheric percent brain water was determined at 24 h. Edema occurred in all groups. Neither PAF receptor antagonist significantly reduced right hemispheric percent brain water (81.08 +/- 0.25 and 81.04 +/- 0.15 in Bn 52021 and WEB 2086-treated rats, respectively, versus 81.31 +/- 0.23 and 81.14 +/- 0.17% brain water in BN 52021 vehicle and WEB 2086 vehicle-treated rats). Mortality was not statistically different between groups. These data do not support a major role for PAF in the development of posttraumatic cerebral edema.

[A phase II study of carboplatin in small cell lung cancer]

A phase II clinical trial of carboplatin for small cell lung cancer was conducted in 20 institutions of the National Chest Hospital lung cancer cooperative study group. Carboplatin was administered by three dosing schedule of 300 mg/m2, 400 mg/m2 and 450 mg/m2. Out of 30 patients registered in this trial, 29 patients were evaluable for response and toxicity. Seven patients achieved PR with the response rate of 24.1%. The response rates for 300 mg/m2, for 400 mg/m2 and for 450 mg/m2 were 25.0%, 8.3% and 44.4%, respectively. Thrombocytopenia (less than 7 x 10(4)/mm3) and leukopenia (less than 3,000/mm3) were observed at 25.9% and 17.2% of cases, respectively. Nausea/vomiting was also observed at an incidence of 55.2% with mild degree. No renal and ototoxic damage was observed.