PATHOLOGICAL ASPECTS OF THE ANTI-INFLAMMATORY/IMMUNE SUPPRESSIVE RESPONSE IN SEPSIS AND SHOCK

Despite the recent advances in contemporary therapeutic, operative as well as supportive care sepsis and its associated co-morbidity/mortality are still a common occurrence in the critically ill trauma/surgical patient. Thus, it remains important to continue to expand our understanding of pathological components which drive the development of immune dysfunction contributing to subsequent multiple organ failure. Here we overview some of the immuno-pathological processes, cells and mediators which may play a role in the development of this immune dysfunctional condition.

Pathological aspects of apoptosis in severe sepsis and shock?

Today, despite the application of contemporary operative/pharmacological approaches in the treatment of the critically ill trauma/surgery patient, we are still faced with a high incidence of patients who develop sepsis and subsequent multiple organ failure. This review attempts to summarize data gathered over the last few years, from both experimental and patient settings, that not only documents the presence of apoptosis, but begins to define its contribution to the pathology of sepsis and shock, which in turn precipitate organ injury/damage.

Shock-induced neutrophil mediated priming for acute lung injury in mice: divergent effects of TLR-4 and TLR-4/FasL deficiency

Acute lung injury (ALI) leading to respiratory distress is a common sequela of shock/trauma, however, modeling this process in mice with a single shock or septic event is inconsistent. One explanation is that hemorrhage is often just a "priming insult," thus, secondary stimuli may be required to "trigger" ALI. To test this we carried out studies in which we assessed the capacity of hemorrhage alone or hemorrhage followed by septic challenge (CLP) to induce ALI. Lung edema, bronchoalveolar lavage interleukin (IL)-6, alveolar congestion, as well as lung IL-6, macrophage inflammatory protein (MIP)-2, and myeloperoxidase (MPO) activity were all increased in mice subjected to CLP at 24 but not 72 hours following hemorrhage. This was associated with a marked increase in the susceptibility of these mice to septic mortality. Peripheral blood neutrophils derived from 24 hours post-hemorrhage, but not Sham animals, exhibited an ex vivo decrease in apoptotic frequency and an increase in respiratory burst capacity, consistent with in vivo "priming." Subsequently, we observed that adoptive transfer of neutrophils from hemorrhaged but not sham-hemorrhage animals to neutropenic recipients reproduce ALI when subsequently septically challenged, implying that this priming was mediated by neutrophils. We also found marked general increases in lung IL-6, MIP-2, and MPO in mice deficient for toll-like receptor (TLR-4) or the combined lack of TLR-4/FasL. However, the TLR-4 defect markedly attenuated neutrophil influx into the lung while not altering the change in local cytokine/chemokine expression. Alternatively, the combined loss of FasL and TLR-4 did not inhibit the increase in MPO and exacerbated lung IL-6/MIP-2 levels even further.

NF-kappaB activation has tissue-specific effects on immune cell apoptosis during polymicrobial sepsis

Studies indicate that critically ill patients who succumb to sequela of sepsis/multiorgan failure, as well as septic animals, exhibit an apparently pathological increase in apoptosis (Ao) in the immune system. However, the mechanisms regulating these changes are unclear. Studies also indicate that, dependent on the cell population and the nature and/or duration of the stimuli, activation of the nuclear factor (NF)-kappaB can either suppress or enhance Ao. Thus, the aim of this study was to determine the contribution of NF-kappaB activation to the onset of Ao seen in divergent immune cell populations during sepsis, as produced by cecal ligation and puncture (CLP). To assess this, C3H/HeN mice were pretreated (for 1 h) subcutaneously with either 100 mg/kg body weight of pyrrolidine dithiocarbamate (PDTC), an NF-kappaB inhibitor, or with saline vehicle, prior to subjecting them to CLP or Sham-CLP (Sham). Thymocytes, phagocytes, and Peyers Patch cells were harvested 24 h later, and the extent of Ao was determined by flow cytometry. The results indicate that PDTC pretreatment had no marked effect on the increase in thymocyte or phagocyte Ao seen following CLP, but there was a significant decline in the extent of Ao observed in septic mouse Peyer's patch B cells. To the extent that this was a result of NF-kappaB inhibition, we demonstrate by Western analysis, electrophoretic mobility shift assay (EMSA) and transfactor assay that the translocation of c-Rel to septic mouse Peyer's patch B cell nuclei is attenuated by PDTC. PDTC pretreatment also markedly reduced the number of Peyer's patch B cells that were producing IgA as well as attenuated the increase of proinflammatory cytokines in the blood. Interestingly, PDTC pretreatment did not restore peritoneal macrophage function or improve animal survival. Taken together, the inability of PDTC pretreatment to alter the Ao response of thymocytes or phagocytes, while inhibiting the increase in Peyer's patch B cell Ao in septic mice, implies not only that the activation of NF-kappaB has highly tissue/cell-specific effects that must be discerned when trying to clarify the pathophysiological role of NF-kappaB in sepsis, but that the activation of NF-kappaB may contribute to the early adaptive responses required by the host to fend off septic challenge.

Mechanism of immune dysfunction in sepsis: inducible nitric oxide-meditated alterations in p38 MAPK activation

BACKGROUND

After the onset of sepsis, there is a marked dysfunction in cell-mediated immunity that contributes to the morbidity and mortality seen in this condition. Although both nitric oxide (NO) from inducible NO synthase (iNOS) and the activation of p38 mitogen-activated protein kinase (p38 MAPK) appear to contribute to this immune dysfunction, the extent to which NO regulates p38 MAPK activity in sepsis remains unknown.

METHODS

To examine this, we induced sepsis by cecal ligation and puncture (CLP) in iNOS knockout (iNOS -/-) or C57BL/6 control mice. Twenty-four hours after CLP or sham operation, splenic T cells and macrophages were isolated and then stimulated with monoclonal antibody against the T-cell marker CD3 (anti-CD3) or lipopolysaccharide. At 4 or 24 hours after stimulation, cytokine release was determined by enzyme-linked immunosorbent assay, and p38 MAPK phosphorylation (activation) was determined by immunoblotting with antibody specific to phosphorylated p38 MAPK.

RESULTS

Splenic T-cell p38 MAPK activation and interleukin (IL)-10 release was increased by CLP, whereas Th1 cytokine (IL-2, interferon-gamma) release was depressed. iNOS gene deficiency inhibited p38 MAPK activation in splenic T cells taken from septic mice, and also suppressed IL-10 release in both sham and septic mice. Interestingly, although deficiency of iNOS restored IL-2 release after CLP, both sham and CLP T cells remained depressed in their ability to release interferon-gamma. Septic insult markedly suppressed C57BL/6 splenic macrophage release of proinflammatory agents tumor necrosis factor, IL-12, and IL-1, while augmenting the release of IL-10. However, although deficiency of iNOS concomitantly restored the ability to produce tumor necrosis factor while suppressing the rise in IL-10 release and p38 MAPK activation, it only partially restored IL-1 release and had no effect on IL-12 production seen after CLP.

CONCLUSION

These data suggest that NO release from iNOS regulates aspects of sepsis-induced immune dysfunction by the activation of p38 MAPK.

239+240Pu and 137Cs concentrations for zooplankton and nekton in the Northwest Pacific and Antarctic Oceans (1993-1996)

The concentrations of 239+240Pu and 137Cs in zooplankton and nekton in the Northwest Pacific and Southern Oceans were measured during the period 1993-1996. The object of the sampling was to assess the potential impacts of existing submerged anthropogenic-radioactive materials in the western North Pacific as well as the East China Sea. Samples from the Bransfield Strait of the Antarctic Ocean provided a control source impacted by only atmospheric bomb fallout. No particularly elevated levels of 239+240Pu were found in zooplankton samples from the Northwest Pacific, although significantly lower levels of 239+240Pu were found in three mixed zooplankton samples from the Bransfield Strait. The body burden of 239+240Pu in zooplankton appears to reflect concentrations in ambient seawater with some variation. Some additional measurements of 137Cs in fish are also reported here to complement existing databases and for future reference in the regional marine environmental radioactivity monitoring effort.

Cyclooxygenase 2-mediated suppression of macrophage interleukin-12 production after thermal injury

Macrophage (Mphi) prostaglandin (PG)E(2) production has been implicated in immunosuppression and increased susceptibility to sepsis after thermal injury. Deficient interleukin (IL)-12 production has also been implicated in these postburn complications. The present study examined the relationship between Mphi cyclooxygenase (COX)-2 activity and IL-12 production after thermal injury. C57BL/6 female mice were subjected to a 25% total body surface area full-thickness burn. Mphi were isolated 7 days later, or the mice were subjected to sepsis by cecal ligation and puncture (CLP). IL-12 production by Mphi from injured mice was suppressed by >50%, whereas COX-2 expression and PGE(2) production were increased twofold. The COX-2 inhibitor NS-398 suppressed PGE(2) production and normalized IL-12 production in the injury group, whereas it had no effect on IL-10 production. Injured mice subjected to CLP had lower IL-12 plasma levels compared with sham-treated mice subjected to CLP. NS-398 treatment prevented the suppression in plasma IL-12 levels in the injury group. Thus elevated Mphi COX-2 activity, independent of IL-10, suppresses Mphi IL-12 production after thermal injury and may play an important role in the observed immunosuppression under such conditions.

Differential alterations in cardiovascular responses during the progression of polymicrobial sepsis in the mouse

Although the mouse has been extensively used to study immune consequences of sepsis and other genetic anomalies, the changes in various cardiovascular parameters such as cardiac output, organ perfusion, as well as oxygen utilization have not been characterized in this species during sepsis. To determine this, polymicrobial sepsis was induced in male adult C3H/NeN mice by cecal ligation and puncture (CLP, two punctures with a 22-gauge needle). The animals were then resuscitated with normal saline subcutaneously. At 5 or 24 h after CLP (time points previously shown to be within the hyperdynamic and hypodynamic stage of sepsis, respectively, in the rat), cardiac output and blood flow in major organs were determined using a well-established radioactive microsphere method, and stroke volume and total peripheral resistance were calculated. In addition, oxygen delivery and consumption were determined. The results indicate that cardiac output, stroke volume, oxygen delivery and consumption, and blood flow in the liver, small intestine, spleen, and kidneys increased significantly at 5 h after CLP. This was associated with significantly decreased total peripheral resistance. In contrast, total peripheral resistance increased and the other above-mentioned parameters, as well as mean arterial pressure, decreased significantly at 24 h after the onset of sepsis. Thus, the cardiovascular response to polymicrobial sepsis in the mouse is characterized by an early hyperdynamic phase (i.e., 5 h after CLP) followed by a late hypodynamic phase (24 h post-CLP). Since the radioactive microsphere technique provides a reliable method for determining various hemodynamic parameters in the mouse, the correlation between the cardiovascular response and immune or potentially genetic alterations can be examined in this species during the progression of sepsis.

A linear cyclic oximate-bridged tetracopper(II) complex

The crystal structure of the title complex, tetrakis[mu-6-amino-3-methyl-4-azahex-3-en-2-one oximato(1-)-kappa4N,N',N":O]tetracopper(II) tetraperchlorate 0.6-hydrate, [Cu4(C6H12N3O)4](ClO4)4*0.6H2O, shows the cation to be an oximate-bridged tetramer composed of four 6-amino-3-methyl-4-azahex-3-en-2-one oxime ligands and four copper(II) ions and to have crystallographically imposed 4 symmetry. Each Cu(II) atom is four-coordinated by the three N atoms of one oxime ligand and by the O atom of another oxime ligand in a distorted square-planar geometry.

The origin of the azygos venous system, as deduced from an anatomical and radiological study employing a corrosion technique

The aim of this study is not only to describe the origin of the human azygos venous system by performing a 3-D reconstruction of a CT scan but also to evaluate the value of the techniques employed in investigating the topographical anatomy of a venous system in the body. Following perfusion with saline to wash away the blood, we injected an ALTUFIX/MINIUM mixture into the azygos vein of a cadaver. The head and trunk were subsequently corroded with hydrochloric acid (HCl). A CT scan of the trunk was obtained both before and after corrosion. According to the spatial resolution of the CT scan, the thinnest identifiable detail was measurable as 0.5 mm. The vertebral lumbar venous system was described, specifying the nomenclature of the lumbar veins (the lumbar veins being designated according to the vertebral body along which they run). On the right side, the lumbar veins at L2 and at L3 formed the lateral root of the azygos vein. On the left side, the vein at L2 formed the reno-azygo-lumbar arch (of Lejars). The lumbar veins, and the origin of the azygos system, were described and compared with previous studies. The 3-D reconstruction showed the importance of veins associated with the posterior paravertebral muscles. This description poses the problem of the metamerisation of the veins, but further evidence is required. Comparisons of the CT scans, 3-D reconstructions, and the ALTUFIX models of the veins obtained from the corrosion technique allowed verification of the 3-D reconstruction and correction of the errors inherent in a computer reconstruction. It is concluded that the description, and understanding, of such a complex system as the vertebral venous system is more valid when the results obtained using different techniques are compared.

MAPK p38 antagonism as a novel method of inhibiting lymphoid immune suppression in polymicrobial sepsis

Although studies indicate that a shift from a Th1 to a Th2 response contributes to a marked suppression of cell-mediated immunity during sepsis, the mechanism by which this occurs remains unknown. Given that the mitogen-activated protein kinase (MAPK) p38 plays a critical role in the activation and function of immune cells, the aim of this study was to determine the contribution of MAPK p38 activation to the immune dysfunction seen in polymicrobial sepsis. To study this, polymicrobial sepsis was induced in C3H/HeN male mice by cecal ligation and puncture (CLP). Splenic lymphocytes and purified T cells were harvested 24 h post-CLP, pretreated with the specific MAPK p38 inhibitor SB-203580, and then stimulated with a monoclonal antibody against the T cell marker CD3. The results indicate that interleukin (IL)-2 release is markedly depressed while the release of the immunosuppressive mediator, IL-10, as well as mRNA levels of IL-10 and IL-4, are augmented after CLP. Inhibition of MAPK p38 suppressed in vitro IL-10 levels as well as IL-10 and IL-4 gene expression while restoring the release of IL-2. To determine whether these in vitro findings could be translated to an in vivo setting, mice were given 100 mg of SB-203580/kg body wt or saline vehicle (intraperitoneal) at 12 h post-CLP. Examination of ex vivo lymphocyte responsiveness indicated that, as with the in vitro finding, septic mouse Th1 responsiveness was restored. In light of our recent finding that delayed in vivo SB-203580 treatment also improved survival after CLP, we believe that these results not only illustrate the role of MAPK p38 in the induction of immunosuppressive agents in sepsis but demonstrate that SB-203580 administration after the initial proinflammatory state of sepsis significantly prevents the morbidity from sepsis.

Inhibition of Fas signaling prevents hepatic injury and improves organ blood flow during sepsis

BACKGROUND

Fas/Fas ligand (FasL) system is one of the major pathways triggering apoptosis that has been shown to play an important role in development and pathogenesis of various diseases including liver and gastrointestinal diseases. Studies indicate that FasL deficiency provides a survival advantage in mice subjected to polymicrobial sepsis. However, the extent to which Fas/FasL contributes to organ injury during sepsis is unclear. Thus, the aim of this study was to determine whether in vivo administration of a Fas-signaling inhibitor during sepsis preserves organ function.

METHODS

Male adult C3H/HeN mice were subjected to cecal ligation and puncture (CLP) or sham CLP (sham). Twelve hours after CLP, mice received either Fas-receptor fusion protein (FasFP) (200 microg/kg body weight) or the saline vehicle. Twenty-four hours after the onset of sepsis, cardiac output and organ blood flow were measured with radioactive microspheres. Plasma levels of alanine aminotransferase, aspartate aminotransferase, and lactate dehydrogenase were assessed as indexes of liver damage. Changes in systemic cytokines were measured by enzyme-linked immunosorbent assay. RESULTS. The data indicate that although cardiac output and organ blood flow in the liver, intestine, kidneys, spleen, and heart decreased markedly at 24 hours after CLP, treatment with FasFP maintained the measured hemodynamic parameters and improved hepatic, intestinal, and heart blood flow (P <.05) and partially restored spleen and renal blood flow. Moreover, FasFP treatment markedly attenuated the systemic rise in alanine aminotransferase, aspartate aminotransferase, lactate dehydrogenase, and interleukin 10 (P <.05).

CONCLUSIONS

These results not only indicate that there is a role for Fas/FasL-mediated processes in the induction of organ injury but suggest that inhibition of Fas/FasL pathway may represent a novel therapeutic modality for maintaining organ perfusion and preventing liver injury during sepsis.

Increased apoptosis in lamina propria B cells during polymicrobial sepsis is FasL but not endotoxin mediated

Recent studies from our laboratory demonstrated that mucosal lymphoid tissue such as Peyer's patch cells and lamina propria (LP) B lymphocytes from mice shows evidence of increased apoptosis after sepsis that is associated with localized inflammation/activation. The mechanism for this is poorly understood. Endotoxin as well as Fas/Fas ligand (FasL) have been shown to augment lymphocyte apoptosis; however, their contribution to the increase of apoptosis in LP B-cells during sepsis is not known. To study this, sepsis was induced by cecal ligation and puncture (CLP) in endotoxin-tolerant C3H/HeJ or FasL-deficient C3H/HeJ-FasL(gld) (FasL(-)) mice and LP lymphocytes were isolated 24 h later. Phenotypic, apoptotic, and functional indexes were assessed. The number of LP B cells decreased markedly in C3H/HeJ mice but not in FasL-deficient animals at 24 h after CLP. This was associated with comparable alteration in apoptosis and Fas antigen expression in the B cells of these mice. Septic LP lymphocytes also showed increased IgA production, which was absent in the FasL-deficient CLP mice. Furthermore, Fas ligand deficiency appeared to improve survival of septic challenge. These data suggest that the increase in B cell apoptosis in septic animals is partially due to a Fas/FasL-mediated process but not endotoxin.

IL-10 mediation of activation-induced TH1 cell apoptosis and lymphoid dysfunction in polymicrobial sepsis

Recent studies suggest that increased activation-induced lymphocyte apoptosis (AICD) is detected in mouse splenocytes during polymicrobial sepsis which may contribute to lymphocyte immune dysfunction [i.e., decreased interleukin (IL-)2 and interferon-gamma (IFN-gamma) production] leading to the associated morbidity seen in those animals. Thus, we wanted to examine the hypothesis that immune suppressive agents, such as IL-4, IL-10 or prostaglandin E2(PGE2), known to be elevated in septic animals, also contribute to this increase in AICD. Here we demonstrate that the inclusion of monoclonal antibody (mAb) to IL-10, but not anti-IL-4 or ibuprofen (IBU), blunted this sepsis induced increase in splenocyte AICD. Additionally, septic mice deficient in the IL-10 gene product (-/-) showed neither an increase in AICD nor a loss of IL-2/IFN-gamma release capacity. Interestingly, mAb to IL-10 did not altered the extent of AICD in a Th2-cell line, but exogenous IL-10 did potentiate Th1-like cell line AICD. This was consistent with the finding that the increased AICD seen in septic mouse splenocytes was restricted largely to the CD4+ cells producing IL-2 (Th1-cells) and that mAb to IL-10 treatment suppressed this change. Furthermore, IL-10 appears to mediate its AICD effect by upregulation of the Fas receptor and Fas receptor signaling protein components, but not by altered expression of Bcl/Bax/Bad family members, in septic mouse splenocytes. To the extent that these processes contribute in a pathological fashion to the animal's capacity to survive sepsis we have previously observed that in vivo post-treatment of mice with mAb IL-10 markedly attenuated septic mortality. Collectively, these data indicate that in the septic mouse the Th2 cytokine IL-10 not only serves to actively induce Th1 lymphocyte immune dysfunction but also plays a role in their apoptotic depletion. These processes in turn appear to contribute to the animal's inability to ward off lethal septic challenge.

Molecular cloning of the porcine acid-labile subunit (ALS) of the insulin-like growth factor-binding protein complex and detection of ALS gene expression in hepatic and non-hepatic tissues

The acid-labile subunit (ALS) is an approximately 85 kDa N-glycoprotein that is known primarily as a component of the systemic insulin-like growth factor-binding protein (IGFBP) complex. We have amplified, using a PCR, three overlapping porcine ALS genomic DNA fragments that together encode the distal region of the signal peptide through to the COOH-terminus. The compiled sequence of 1775 nucleotides of the three overlapping DNAs and the deduced amino acid sequence of the mature porcine ALS (pALS) protein exhibited 84/81%, 79/77%, 79/78% and 84/79% identities with respect to those of the human, the rat, the mouse and the baboon respectively. Four conserved cysteine residues in the NH(2)-terminal domain and 20 leucine-rich repeats in the central domain also were identified at identical positions in the porcine ALS. By using Northern blot analysis, with a genomic DNA fragment as the probe, it was determined that a 2.2 kb ALS mRNA was induced in the liver during the late fetal stage, and hepatic ALS mRNA abundance was increased post-natally. Moreover, hepatic ALS mRNA abundance was increased by daily injection of porcine somatotropin (100 microg/kg body weight) in cross-bred market pigs each weighing approximately 100 kg. The ALS mRNA was not detected by Northern analysis in any non-hepatic tissue examined. However, results of a more sensitive solution hybridization/RNAse protection assay indicated that low levels of ALS mRNA were also present in adult muscle, spleen, ovary and uterus, but not in lung, kidney, oviduct and placenta. Taken together, the present results suggest that although liver is the primary organ that expresses the ALS gene under somatotropin stimulation, some non-hepatic tissues also express the gene at low levels in the pig.

Evolution of an immune suppressive macrophage phenotype as a product of P38 MAPK activation in polymicrobial sepsis

Studies indicate that polymicrobial sepsis in humans and animals is characterized by a biphasic response, which is dominated early by proinflammation, but over time develops into a state of generalized anti-inflammation (depressed Th1 cell response and decreased macrophage (M0) capacity to release proinflammatory cytokines). However, with respect to the macrophage, it remains unknown what mechanism(s) controls this change. In this regard it is well documented that the p38 mitogen activated protein kinase pathway (MAPK) plays a central role in the regulation of Mphi functions. However, the contribution of p38 MAPK activation to the loss of these Mphi functions in polymicrobial septic animals remains unknown. To determine this we induced polymicrobial sepsis in C3H/HeN male mice using cecal ligation and puncture (CLP). Twenty-four hours post-CLP, during the late, immune-suppressed stage of sepsis, splenic and peritoneal Mphi were harvested, stimulated with lipopolysaccharide (LPS), and the activation of p38 MAPK assessed. In Mphi from CLP mice, p38 MAPK activity was markedly increased. To determine the extent that these changes in p38 MAPK had an impact on Mphi immune function, cells were pretreated with 10 microM of the p38 MAPK inhibitor, SB203580, or with DMSO vehicle, and subsequently stimulated with LPS. IL-10, IL-6, IL-12, and nitric oxide release was determined. Our results indicate that with LPS stimulation alone, there was a marked increase in the release of the anti-inflammatory mediator, IL-10 after CLP. Alternatively, proinflammatory IL-12 and IL-6 release was suppressed. Treatment with SB203580 suppressed the increase in IL-10 release seen after CLP, while partially restoring IL-12 secretion. IL-6 release was partially restored only in splenic macrophages treated with SB203580. To the extent that these in vitro findings could be translated to an in vivo setting, we assessed the in vivo effects of p38 MAPK inhibition on survival. Mice were given 100 mg of SB203580/kg body weight or saline vehicle (intraperitoneal) either immediately post-CLP or 12 h post-CLP. Delayed administration of SB203580 significantly improved survival, while also preventing the increased NO and IL-10 release and improving IL-12 release by macrophages. These results suggest that p38 MAPK pathway plays a critical role in the induction of an immune-suppressive macrophage phenotype, and that inhibition of p38 MAPK markedly improves survival following polymicrobial sepsis.

Striatocapsular haemorrhage

Haemorrhages in the striatocapsular area, or striatocapsular haemorrhages (SCHs), have been regarded as a single entity, although the area is composed of several functionally discrete structures that receive blood supply from different arteries. We analysed the morphological and clinical presentations of 215 cases of SCHs according to a new classification method we have designed on the basis of arterial territories. SCHs were divided into six types: (i) anterior type (Heubner's artery); (ii) middle type (medial lenticulostriate artery); (iii) posteromedial type (anterior choroidal artery); (iv) posterolateral type (posteromedial branches of lateral lenticulostriate artery); (v) lateral type (most lateral branches of lateral lenticulostriate artery); and (vi) massive type. The anterior type (11%) formed small caudate haematomas, always ruptured into the lateral ventricle, causing severe headache, and mild contralateral hemiparesis developed occasionally. The outcome was excellent. The middle type (7%) involved the globus pallidus and medial putamen, frequently causing contralateral hemiparesis and transient conjugate eye deviation to the lesion side. About 50% of the patients recovered to normal. The posteromedial type (4%) formed very small haematomas in the posterior limb of the internal capsule and presented with mild dysarthria, contralateral hemiparesis and sensory deficit, with excellent outcome in general. The posterolateral type (33%) affected the posterior half of the putamen and posterior limb of the internal capsule and presented with impaired consciousness and contralateral hemiparesis with either language dysfunction or contralateral neglect. The outcome was fair to poor but there were no deaths. The lateral type (21%) formed large elliptical haematomas between the putamen and insular cortex. Contralateral hemiparesis with language dysfunction or contralateral neglect developed frequently but resolved over several weeks. The clinical outcome was relatively excellent except when the haematoma size was very large. The massive type (24%) formed huge haematomas affecting the entire striatocapsular area. Marked sensorimotor deficits and impaired consciousness, ocular movement dysfunctions including the 'wrong-way' eyes were observed quite frequently. The outcome was very poor with a case fatality rate of 81%. The clinico-radiological presentations suggested its origin was the same as the posterolateral type.

Cell-cycle arrest at G2/M and growth inhibition by apigenin in human colon carcinoma cell lines

Apigenin, a common dietary flavonoid, has been shown to induce cell cycle arrest in both epidermal and fibroblast cells and inhibit skin tumorigenesis in murine models. The present study assessed the influence of apigenin on cell growth and the cell cycle in the human colon carcinoma cell lines SW480, HT-29, and Caco-2. Treatment of each cell line with apigenin (0-80 microM) resulted in a dose-dependent reduction in both cell number and cellular protein content, compared with untreated control cultures. DNA flow cytometric analysis indicated that treatment with apigenin resulted in G2/M arrest in all three cell lines in a time- and dose-dependent manner. Apigenin treatment (80 microM) for 48 h produced maximum G2/M arrest of 64%, 42%, and 26% in SW480 cells, HT-29 cells, and Caco-2 cells, respectively, in comparison with control cells (15%). The proportion of S-phase cells was not altered by apigenin treatment in each of the three cell lines. The G2/M arrest was reversible after 48 h of apigenin treatment in the most sensitive cell line SW480. The degree of G2/M arrest by apigenin was inversely correlated with the corresponding inhibition of cell growth measurements in all three cell lines (r = -0.626 to -0.917, P</=0. 005). Moreover, an immune complex kinase assay demonstrated an inhibition of p34(cdc2) kinase activity, a critical enzyme in G2/M transition, in each cell line after treatment with apigenin (50-80 microM). Western blot analyses indicated that both p34(cdc2) and cyclin B1 proteins were also decreased after apigenin treatment. These results indicate that apigenin inhibits colon carcinoma cell growth by inducing a reversible G2/M arrest and that this arrest is associated, at least in part, with inhibited activity of p34(cdc2) kinase and reduced accumulation of p34(cdc2) and cyclin B1 proteins. Differences in induction of G2/M arrest by apigenin in the three colon carcinoma cell lines suggest that dietary apigenin may be differentially effective against tumors with specific mutational spectra. Mol. Carcinog. 28:102-110, 2000.

Immune depression in polymicrobial sepsis: the role of necrotic (injured) tissue and endotoxin

OBJECTIVE

Recent studies suggest immune dysfunction seen after the onset of polymicrobial sepsis, as produced by cecal ligation and puncture (CLP), is not caused by endotoxin (ETX) alone, but may be caused by the combined effect of the necrotic tissue (cecal ligation, [CL]) and other microbial components. Thus, the objective of this study was to assess the ability of necrotic tissue, in the presence or absence of low-dose endotoxin, to induce changes in the capacity of immune cells to produce proinflammatory or anti-inflammatory cytokines approximating those seen in CLP.

DESIGN

Experimental, prospective study.

SETTING

A hospital laboratory in the Center for Surgical Research.

SUBJECTS

Male C3H/HeN mice.

INTERVENTIONS

Mice were subjected to a CL and saline infusion (CL/Sal), CL in combination with low-dose ETX infusion (CL/ETX) (0.025 mg ETX/25 g body weight/24 hrs by a peritoneally implanted osmotic mini-pump), ETX infusion alone, saline infusion alone (Sal), CLP, or sham-CLP (Sham). Splenocytes, splenic macrophage and peritoneal macrophage were harvested from these animals 24 hrs (late) after being subjected to the above protocols. Splenocyte and macrophage inducible cytokine release was assessed by ELISA/bioassay. Survival over a 7-day period was also examined in additional groups.

MEASUREMENTS AND MAIN RESULTS

Our results indicate a marked decrease in splenic interleukin (IL)-2. In addition, peritoneal or splenic macrophage IL-6 productive capacity was depressed in cells from animals subjected to CL/ETX or CLP. Alternatively, CL, in the presence or absence of ETX, induced a marked change in macrophage cytokine release capacity comparable to that seen in CLP, ie, decreased IL-12 release and increased IL-10 secretion. To the extent these cellular alterations contribute to an increase in mortality rate, we observed in subsequent survival studies that neither CL alone nor ETX produced mortality. However, the combination of CL/ETX markedly increased 7-day mortality rate (approximately 33%), although not to the same extent as CLP (80%).

CONCLUSIONS

These results collectively suggest that the response to devitalized tissue produced by cecal ligation may predispose the host to the induction of a suppressive macrophage phenotype. The subsequent exposure of these animals to microbial agents induces immune dysfunction, as well as mortality seen after such a polymicrobial septic challenge.

IL-4-induced activation of the Stat6 pathway contributes to the suppression of cell-mediated immunity and death in sepsis

BACKGROUND

Although studies have shown that there is a marked depression in cell-mediated (T(H)(1)) immunity after the onset of sepsis, the mechanism by which this occurs remains unknown. In this regard, the T(H2) cytokine IL-4 is known to regulate T(H1) and T(H2) cell responsiveness primarily through the activation of the signal transducer and activation of transcription factor-6 (Stat6) pathway.

METHODS

We hypothesized that IL-4 may contribute to the suppression of cell-mediated immunity and to death seen in sepsis and that IL-4 may be acting through the Stat6 pathway. To determine this, we induced cecal ligation and puncture (CLP) or sham-CLP in male BALB/c mice. Mice received 2 mg of monoclonal antibody against IL-4 or IgG control at 12 hours after CLP (ie, at the onset of immune suppression). Splenic T cells were then isolated 24 hours after CLP and stimulated with monoclonal antibody to CD3. Cytokine release and Stat6 phosphorylation (activation) were determined. In a separate group of animals, survival was assessed over 10 days.

RESULTS

The results indicate that after CLP, T cells are suppressed in their ability to release the T(H1) cytokines, IL-2 and IFN-gamma. Alternatively, the release of T(H2) cytokines IL-10 and IL-4 is markedly increased after CLP. This was associated with an increase in phosphorylated Stat6 protein. In vivo treatment of mice with monoclonal antibody to IL-4 at 12 hours after CLP restores T(H1) responsiveness while preventing the increase in T(H2) cytokine release and Stat6 phosphorylation. Furthermore, neutralization of IL-4 markedly increased the survival rates in septic animals.

CONCLUSIONS

Taken together, these data indicate that the T(H2) cytokine IL-4 contributes to the suppression of cell-mediated immunity and death associated with polymicrobial sepsis and suggest that IL-4 may be acting through the Stat6 pathway in septic animals.

Prevalence and risk factors of silent cerebral infarction in apparently normal adults

Cerebrovascular disease is a major cause of death and disability in adults. Silent cerebral infarction (SCI) portends more severe cerebral infarctions or may lead to insidious progressive brain damage resulting in vascular dementia. This study was designed to evaluate the prevalence and risk factors of SCI in an apparently normal adult population. Nine hundred ninety-four consecutive symptom-free adults (mean age 49.0+/-7.7; men:women 830:164) who underwent brain magnetic resonance imaging at the Center for Health Promotion at Samsung Medical Center were assessed. All were neurologically normal in history and physical examination. A total of 121 SCI lesions was observed in 58 subjects. The lesion prevalence adjusted for patient age was 5.1%. There was no gender difference in prevalence. Ninety-nine lesions were <1 cm in diameter, 15 were between 1 and 2 cm, 3 were between 2 and 3 cm, and 4 were >3 cm in diameter. The most frequent site of the SCI lesion was basal ganglia, after which the periventricular white matter, cerebral cortex, and thalamus were the most frequent sites. Old age, hypertension, a history of coronary artery disease, evidence of cardiomegaly in chest radiographs, and high fasting glucose/hemoglobin A1c levels were associated with SCI on univariate analysis. Multivariate analysis demonstrated old age and hypertension to be independent risk factors for SCI, and mild alcohol consumption was revealed as an independent protective factor against SCI.

Usefulness of triphasic perfusion computed tomography for intravenous thrombolysis with tissue-type plasminogen activator in acute ischemic stroke

BACKGROUND

Intravenous thrombolysis for acute ischemic stroke has been investigated in several clinical trials without enough information on collateral blood flow and perfusion deficit in the ischemic areas. The therapeutic time window varies from patient to patient depending on these factors. Triphasic perfusion computed tomography (TPCT) can provide this information as reliably as conventional angiography.

OBJECTIVE

To assess the safety and efficacy of thrombolysis within 3 or 7 hours of stroke onset according to the extent of perfusion deficit on TPCT.

METHODS

In 46 patients with acute middle cerebral artery (MCA) territory stroke, TPCT was performed with power injector-controlled, intravenous administration of contrast media after taking precontrast CT scans. Sequential scans of early, middle, and late phases were performed. The entire procedure took 5 minutes. Depending on collateral blood flow, the perfusion deficit on TPCT was graded as "severe perfusion deficit" or "moderate perfusion deficit." Twenty-nine patients were excluded based on clinical, laboratory, and TPCT findings. Seventeen patients were treated with an intravenous recombinant tissue-type plasminogen activator, 0.9 mg/kg. The 17 treated patients were divided into 2 groups: group 1 with small severe perfusion deficit (</=33% of the presumed MCA territory) and group 2 with medium-sized severe perfusion deficit (>33% but </=50% of the presumed MCA territory). The 13 patients in group 1 were treated within 7 hours of onset and the 4 patients in group 2 were treated within 3 hours.

RESULTS

Initial mean National Institutes of Health Stroke Scale score was 12.1 (range, 6.0-20.0) in group 1 and 19.0 (range, 18.0-21. 0) in group 2. The initial score correlated better with the total extent of moderate perfusion deficit and severe perfusion deficit than that of severe perfusion deficit alone. Mean time lapse to thrombolysis was 4.2 hours (range, 1.5-7.0 hours) in group 1 and 2.2 hours (range, 1.9-2.5 hours) in group 2. Eight patients (47%), 7 from group 1 and 1 from group 2, improved by 4 points or more from baseline Stroke Scale score within 24 hours of thrombolysis. Patients with moderate perfusion deficit of 50% or more of MCA territory (n = 4) had a better chance of early improvement than did those (n = 13) with moderate perfusion deficit of less than 50% (4 of 4 vs 4 of 13). No fatal hemorrhage occurred. Only 1 patient (6%) had symptomatic small basal ganglia hemorrhage after thrombolysis.

CONCLUSIONS

Thrombolysis can be safely performed within 3 or 7 hours of stroke onset according to the extent of severe perfusion deficit on TPCT. A larger extent of moderate perfusion deficit on TPCT may predict early improvement after thrombolysis.

Triphasic perfusion computed tomography in acute middle cerebral artery stroke: a correlation with angiographic findings

OBJECTIVE

To evaluate the usefulness of triphasic perfusion computed tomography (TPCT) in diagnosing middle cerebral artery (MCA) occlusion and in assessing the perfusion deficit and collateral circulation in patients with acute ischemic stroke.

BACKGROUND

Conventional angiography is the criterion standard for the diagnosis of MCA occlusion and for the assessment of perfusion deficit and collateral blood supply. The risk of hemorrhagic transformation after recanalization of occluded arteries by thrombolytic therapy is considered high when pretherapeutic residual flow is markedly reduced.

PATIENTS AND METHODS

In 8 patients within 3 hours of onset of acute MCA stroke, precontrast computed tomographic scans were taken, and then TPCT was performed after power-injector controlled intravenous administration of contrast media. Sequential images of early, middle, and late phases were obtained. The whole procedure took 5 minutes. Perfusion deficit on TPCT was graded as "severe" or "moderate," depending on the state of collateral flow. Digital subtraction angiography (DSA) was performed in all patients within 6 hours of acute stroke. Direct intra-arterial urokinase infusion was begun immediately after the angiographic superselection of the MCA occlusion site in 6 of the 8 patients within 7 hours of onset (range, 4.3-6.2 hours).

RESULTS

The DSA findings showed occlusion of the MCA stem (n = 1) and at the bifurcation (n = 4). The sites of proximal MCA occlusion could be identified on the early and middle images of TPCT in all 5 patients. On DSA findings, all 8 patients had a zone of perfusion deficit with markedly slow leptomeningeal collaterals and a zone of perfusion deficit with no collaterals. The zone of severe perfusion deficit on TPCT corresponded to the zone of perfusion deficit with no or few collaterals on angiography, and the zone of moderate perfusion deficit on TPCT corresponded to that of perfusion deficit with markedly slow leptomeningeal collaterals. Early parenchymal hypoattenuation on precontrast computed tomography was confined to the zone of severe perfusion deficit on TPCT. The initial National Institutes of Health Stroke Scale score correlated better with the total extent of severe perfusion deficit and moderate perfusion deficit on TPCT than that of severe perfusion deficit alone. After direct intra-arterial thrombolysis within 7 hours of onset, symptomatic hemorrhagic transformation did not develop in 4 patients with small severe perfusion deficit (33% or less of the presumed MCA territory). However, the remaining 2 patients with large severe perfusion deficit (more than 50% of the presumed MCA territory) deteriorated to death with hemorrhagic transformation.

CONCLUSIONS

Triphasic perfusion computed tomography is useful for diagnosing proximal MCA occlusion and assessing perfusion deficit and collateral circulation as reliably as DSA. The zone of severe perfusion deficit on TPCT may be presumed to be the ischemic core, and that of moderate perfusion deficit, the penumbra zone. Triphasic perfusion computed tomography may be used as a rapid and noninvasive tool to make thrombolysis safer.

Neither Fas ligand nor endotoxin is responsible for inducible peritoneal phagocyte apoptosis during sepsis/peritonitis

Regulation of the phagocyte apoptotic response appears to play a significant role in the pathophysiology of sepsis. In this regard, prior studies have shown that the onset of phagocyte apoptosis, as well as those agents that regulate it at the nidus of infection, differ significantly from those seen in circulation. The aim of this study therefore was to determine if the increase in inducible phagocyte apoptosis and caspase activities seen in the peritoneum during sepsis is due to endotoxin or Fas ligand. To study this, male C3H/HeN (endotoxin-sensitive), C3H/HeJ (endotoxin-tolerant), and C3H/HeJ-FasL(gld) (endotoxin-tolerant/FasL-deficient) mice were subjected to cecal ligation and puncture or sham operation. Twenty-four hours later, phagocytes were collected and cultured with lipopolysaccharide (LPS), then harvested for apoptosis (propidium iodide cell cycle or cell death ELISA analysis), cytokine release (ELISA), and caspase activity (fluorogenic assay) determination. The data indicate that there was a marked increase in apoptosis in LPS-stimulated phagocytes which was associated with a significant increase in caspase 3, 8, and 9 activities but a decrease in caspase 1 activity from C3H/HeN and C3H/HeJ-FasL(gld) septic mice and an increase in caspase 3 and 8 activities in phagocytes from C3H/HeJ septic mice. Furthermore, cells from septic mice, including all three strains, lost their ability to produce IL-1beta and IL-6 in response to LPS stimulation. The inability to completely suppress these changes suggests that neither endotoxin (via signaling through TLR-4 pathway) nor Fas ligand regulates the peritoneal phagocyte apoptotic responses seen during the late phase of polymicrobial sepsis/peritonitis.

Immune suppression in polymicrobial sepsis: differential regulation of Th1 and Th2 responses by p38 MAPK

BACKGROUND

Studies have indicated that a shift from a Th1 to a Th2 response occurs that contributes to the late immunosuppression seen during sepsis. However, the mechanism by which this occurs is unknown. In this regard, mediators released in response to sepsis are thought to upregulate a family of stress-induced mitogen-activated protein kinases (MAPKs), such as JNK, ERK, and p38 MAPK, which may play a role in this process.

MATERIALS AND METHODS

To determine the role of MAPK in immune suppression, we induced polymicrobial sepsis in C3H/HeN male mice using cecal ligation and puncture (CLP). Splenic lymphocytes were harvested 24 h post-CLP and stimulated with the T-cell mitogen concanavalin A, and the expression and activation of these MAPKs were assessed by Western analysis. To determine the extent to which these MAPKs may have an impact on splenic immune function, cells were pretreated with a 10 microM concentration of the p38 MAPK inhibitor SB203580 or the MEK inhibitor PD98059 or with DMSO vehicle. The cells were then stimulated with 2.5 microg/ml of the T-cell mitogen concanavalin A, and cytokine release was then determined (by ELISA).

RESULTS

In the lymphocytes from CLP mice no JNK signal was detected, however, p38 expression and activation were markedly (P < 0.05, n = 6) increased. In contrast, the expression of activated ERK markedly decreased following septic challenge. The results indicate that p38 MAPK inhibition with SB203580 suppressed the sepsis-induced augmentation of interleukin-10 release while restoring the suppressed Th1 cytokine interleukin-2 release typically encountered following sepsis. Inhibition of ERK had no effect on cytokine release. Neither PD98059 nor SB203580 had an effect on interferon gamma release or on proliferative capacity.

CONCLUSION

This would indicate that the induction of p38 MAPK activation in splenocytes contributes to the immunosuppression seen in late sepsis.

Septic mucosal intraepithelial lymphoid immune suppression: role for nitric oxide not interleukin-10 or transforming growth factor-beta

OBJECTIVE

Recent studies indicate that sepsis induces a marked depression in the splenocyte immune response (as illustrated by decreased interleukin [IL]-2 production, interferon [IFN]-gamma production, or both) in response to T-cell mitogen. However, it is not known whether a similar depression is evident in the phenotypically distinct, small intestine intraepithelial lymphocytes (IELs) or what regulates this process during sepsis. Because the maintenance of a competent mucosal immune response is thought to be central to the animal's ability to survive sepsis, we attempted to determine whether IEL's IL-2/IFN-gamma production is suppressed and what mediates this depression.

RESULTS

Our studies indicated that C3H/HeN mice subjected to cecal ligation and puncture (CLP) exhibited a marked decline in the ability of IELs to release IL-2/IFN-gamma at 24 hours and that this decline is associated with increased secretion of IL-10 and nitric oxide (NO). To the extent that IL-10 accounted for this loss of IL-2/IFN-gamma release, we observed that IL-10 gene deficiency neither restored the IL-2/IFN-gamma release nor suppressed the increase in NO when compared with background control, C57BL/6J mouse cells. To further study whether NO was involved in this immune suppression, iNOS knockout (iNOS -/-) were also subjected to the same procedure; however, the depression in IL-2/IFN-gamma was not seen in iNOS -/- mice when compared with background controls.

CONCLUSION

Our data indicate that IL-10, which affects splenic lymphoid response, may not be a key mediator of IEL immune suppression and that the induction of NO may play a more significant role in gastrointestinal immune dysfunction seen in late sepsis.

Early renal ischemia, with or without reperfusion, activates NFkappaB and increases TNF-alpha bioactivity in the kidney

PURPOSE

Acute tubular necrosis (ATN) and the ensuing renal failure induced by ischemia and reperfusion injury (I/R) remain a major cause of morbidity and mortality among patients in the intensive care unit. Although it is well established that exogenous tumor necrosis factor-alpha (TNF) induces renal injury, it remains unknown whether ischemia and/or reperfusion activates the signaling mechanisms required for renal TNF production. We hypothesized that ischemia and/or reperfusion would activate the oxidant sensitive TNF transcription factor, nuclear factor kappa B (NFkappaB), and thereby lead to renal TNF production.

MATERIALS AND METHODS

Male Sprague-Dawley rats were anesthetized with sodium pentobarbital, after which various periods of renal ischemia, with or without reperfusion, were induced in rats. At different time intervals, kidneys were harvested and NFkappaB activation (electrophoretic mobility shift assay), TNF mRNA content (RT-PCR), and TNF bioactivity (WEHI-164 cell clone cytotoxicity assay) were determined.

RESULTS

Results indicate that 15 minutes of ischemia alone activates NFkappaB, whereas peak activation occurred at 30 minutes of ischemia alone. NFkappaB remained activated through 60 minutes reperfusion. Thirty minutes of ischemia is required to induce renal TNF mRNA production; however, renal TNF protein expression and bioactivity peaked following 1 hour of ischemia and 2 hours reperfusion.

CONCLUSIONS

These results are the initial demonstration that renal ischemia, with or without reperfusion, activates the TNF transcription factor NFkappaB and increases TNF bioactivity in the kidney.

Early renal ischemia, with or without reperfusion, activates NFkappaB and increases TNF-alpha bioactivity in the kidney

PURPOSE

Acute tubular necrosis (ATN) and the ensuing renal failure induced by ischemia and reperfusion injury (I/R) remain a major cause of morbidity and mortality among patients in the intensive care unit. Although it is well established that exogenous tumor necrosis factor-alpha (TNF) induces renal injury, it remains unknown whether ischemia and/or reperfusion activates the signaling mechanisms required for renal TNF production. We hypothesized that ischemia and/or reperfusion would activate the oxidant sensitive TNF transcription factor, nuclear factor kappa B (NFkappaB), and thereby lead to renal TNF production.

MATERIALS AND METHODS

Male Sprague-Dawley rats were anesthetized with sodium pentobarbital, after which various periods of renal ischemia, with or without reperfusion, were induced in rats. At different time intervals, kidneys were harvested and NFkappaB activation (electrophoretic mobility shift assay), TNF mRNA content (RT-PCR), and TNF bioactivity (WEHI-164 cell clone cytotoxicity assay) were determined.

RESULTS

Results indicate that 15 minutes of ischemia alone activates NFkappaB, whereas peak activation occurred at 30 minutes of ischemia alone. NFkappaB remained activated through 60 minutes reperfusion. Thirty minutes of ischemia is required to induce renal TNF mRNA production; however, renal TNF protein expression and bioactivity peaked following 1 hour of ischemia and 2 hours reperfusion.

CONCLUSIONS

These results are the initial demonstration that renal ischemia, with or without reperfusion, activates the TNF transcription factor NFkappaB and increases TNF bioactivity in the kidney.

Aspiration subsequent to a pure medullary infarction: lesion sites, clinical variables, and outcome

BACKGROUND

Aspiration as a symptom of dysphagia and its apparent sequela, aspiration pneumonia, are common consequences of a stroke in the medulla. Previous reports that focused on dysphagia due to a medullary lesion were studies of single cases or a relatively small number of patients with multiple lesion loci. Moreover, the interval between the onset of stroke and the evaluation time of swallowing was not controlled and varied largely among patients. Thus, prediction of the swallowing status of patients with a medullary lesion has not been tenable.

OBJECTIVES

To investigate the relation between the loci of pure medullary lesions and aspiration, to examine swallowing function over time, and to explore clinical variables that can predict aspiration.

METHODS

We investigated 23 patients with pure medullary infarctions using the videofluoroscopic swallowing study and compared the airway status findings with the lesion location as determined with magnetic resonance imaging. The patients were classified by 6 medullary lesion-level categories (lower, lower-middle, middle, lower-middle-upper, middle-upper, and upper) and by 5 intralevel lesion loci (inferior-dorsal, large inferior-dorsolateral, para-median, midlateral, and dorsolateral). From the results of the videofluoroscopic swallowing studies, 2 patient groups were formed: one with aspiration and the other without aspiration. The clinical variables related to aspiration and outcome measures were also explored.

RESULTS

Ten (44%) of the 23 patients manifested aspiration on swallowing: 9 (69%) of 13 with only middle-level lesions or lesions in multilevels, including the middle level; 1 (33%) of 3 with only upper-level lesions; and 0 (0%) of 7 with only lower-level medullary lesions. A lesion running the length of the middle and the lower medullary levels always resulted in aspiration. When an upper-level lesion was additionally involved, the incidence of aspiration depended on the horizontal extension of the lesion. We were able to discriminate the 2 patient groups with 95.7% accuracy using such variables as dysphonia, soft palate dysfunction, and facial hypesthesia. Most of the patients with aspiration symptoms due to a pure medullary infarction recovered rather quickly.

CONCLUSIONS

Medullary infarctions often cause aspiration, but the occurrence may depend on the levels along the neuraxis and intralevel lesion loci. When different lesion levels and loci and their related clinical findings are considered as possible variables, aspiration becomes predictable. The outcome data prove that systematic control of evaluation time of swallowing was critical as we engaged in this study, since many aspirators with pure medullary infarctions resolve their swallowing difficulties rather quickly.

Vaccinia virus envelope H3L protein binds to cell surface heparan sulfate and is important for intracellular mature virion morphogenesis and virus infection in vitro and in vivo

An immunodominant antigen, p35, is expressed on the envelope of intracellular mature virions (IMV) of vaccinia virus. p35 is encoded by the viral late gene H3L, but its role in the virus life cycle is not known. This report demonstrates that soluble H3L protein binds to heparan sulfate on the cell surface and competes with the binding of vaccinia virus, indicating a role for H3L protein in IMV adsorption to mammalian cells. A mutant virus defective in expression of H3L (H3L(-)) was constructed; the mutant virus has a small plaque phenotype and 10-fold lower IMV and extracellular enveloped virion titers than the wild-type virus. Virion morphogenesis is severely blocked and intermediate viral structures such as viral factories and crescents accumulate in cells infected with the H3L(-) mutant virus. IMV from the H3L(-) mutant virus are somewhat altered and less infectious than wild-type virions. However, cells infected by the mutant virus form multinucleated syncytia after low pH treatment, suggesting that H3L protein is not required for cell fusion. Mice inoculated intranasally with wild-type virus show high mortality and severe weight loss, whereas mice infected with H3L(-) mutant virus survive and recover faster, indicating that inactivation of the H3L gene attenuates virus virulence in vivo. In summary, these data indicate that H3L protein mediates vaccinia virus adsorption to cell surface heparan sulfate and is important for vaccinia virus infection in vitro and in vivo. In addition, H3L protein plays a role in virion assembly.

The relationship between the angiographic findings and the clinical features of carotid artery plaque

The purpose of this study was to investigate the histological characteristics of atheromatous carotid plaque, and to analyze the relationship between the angiographic findings and the clinical features. We retrospectively reviewed 55 cases of carotid endarterectomy for extracranial internal carotid artery stenosis, who were treated at our institute from January 1995 to December 1997. The histological examination included hematoxylin-eosin staining, Masson-trichrome staining, and immunostaining for antismooth muscle antibody and anti-CD68 antibody. The main compositions of the carotid plaque included synthetic type vascular smooth muscle cells and extracellular matrix. The histological findings showed ulceration in 49 (89.1%) cases, calcium deposits in 42 (76.4%) cases, and an inflammatory reaction in 44 (80.0%) cases. Neurological abnormalities were strongly associated with plaque ulceration (P = 0.045) and an inflammatory reaction (P = 0.013), whereas no correlation existed regarding calcium deposits (P = 0.173). The angiographic findings showed ulceration in 46 (83.6%) cases. Plaque ulceration in the angiography findings showed no statistically significant correlation with the histologic findings (P = 0.410) and preoperative neurologic abnormalities (P = 0.059). All of the atherosclerotic risk factors such as hypertension, smoking, diabetes mellitus, hyperlipidemia, and myocardial infarction had no statistically significant correlation with the histological features of the carotid plaque. In conclusion, the main compositions of carotid plaque were synthetic-type vascular smooth muscle cells and extracellular matrix. The histological ulceration and inflammatory reaction of the plaque showed a statistically significant correlation with the preoperative neurologic symptoms, whereas no correlation was seen in the calcium deposits. Angiographic ulceration showed no correlation with the histological findings or preoperative neurologic abnormalities. In addition, the histological findings showed no correlation with the atherosclerotic risk factors.

Synthesis and structural characterization of a Re(V) complex with a 2N1S donor and the radiochemical behavior of its Tc analog

A rhenium(V) complex with 2-(2-pyridylmethylthio)-aniline has been synthesized and characterized by UV-VIS absorption, IR, MS and X-ray crystallography. The complex contains a ReO3+ moiety and the amine compound, acting as a monobasic tridentate(NSN) ligand. The chemical behavior of its technetium analog has been studied radioanalytically by solvent extraction, TLC, electrophoresis and HPLC using 99mTc tracer.

Diffusion-weighted MRI in vascular dementia

OBJECTIVE

To examine the ability of diffusion-weighted MRI (DWI) to detect ongoing cerebral ischemia in patients with vascular dementia (VaD).

BACKGROUND

VaD due to small-vessel disease results from the cumulative impact of recurrent cerebral ischemia. Cerebral ischemia may produce clinical manifestations, producing the "stepwise" decline characteristic of VaD. Conventional MRI can detect small regions of ischemic damage but cannot determine when injury developed. In contrast, DWI shows sensitivity in detecting ischemia of recent onset.

DESIGN/METHODS

Patients with VaD (n = 30) underwent DWI in addition to standard MRI sequences. Patients were divided into two groups according to the presence of new focal deficits or mental change within 10 days before MRI. In 10 patients of positive group, symptomatic neurologic decline occurred an average of 4.2 days before the imaging procedure.

RESULTS

Seven (70%) of 10 patients with a recent neurologic event showed 15 new regions of signal abnormality on DWI. The anatomic distribution of signal change could account for the patients' new symptoms or signs in all but one patient. Similar signal abnormality was detected in 4 (20%) of 20 patients without a recent neurologic event. New foci of altered signal intensity were distinguishable from prior injuries only with DWI. No significant difference was found between patients with and without DWI abnormalities in gender, age, Mini-Mental State Examination score, Hachinski Ischemic Score, vascular risk factors, or severity of increased signal on T2-weighted MRI scans.

CONCLUSION

Small foci of abnormal signal on diffusion-weighted MRI (DWI), presumably representing recent small infarcts, occur often in vascular dementia (VaD) from small-vessel disease, even in patients without a recent "stepwise decline." The results suggest that DWI might be used to monitor VaD progression in future observational and interventional studies of this disorder.

Cancer and cardiac mortality among 15-year survivors of cancer diagnosed during childhood or adolescence

PURPOSE

To evaluate the impact of cardiac disease and second malignant neoplasms on late mortality rate and to identify risk factors for late mortality among 15-year survivors of cancer diagnosed during childhood or adolescence.

PATIENTS AND METHODS

Gender-specific all-cause and cause-specific (cardiac disease, cancer) standardized mortality ratios were calculated. Kaplan-Meier survival estimates and Cox regression analyses were performed to determine the relationship of several demographic and treatment variables to survival.

RESULTS

Patients who survived for 15 years after diagnosis had excess subsequent all-cause, cancer (second malignant neoplasms only), and cardiac mortality rates. No decrease in the late mortality rate by treatment era (1960 to 1970, 1971 to 1984) was identified. Risk factors for males included disease recurrence during the first 15 years after diagnosis, treatment with doxorubicin, and the diagnosis of Hodgkin's disease. Those for females included treatment with radiation therapy, treatment with an alkylating agent, and disease recurrence during the first 15 years after diagnosis. Cox regression analysis demonstrated that only an initial duration of remission of less than 15 years (P <.01) and treatment with doxorubicin (P =.08) were significantly associated with shorter survival time for males. No variable was significantly associated with shorter survival time for females in Cox regression analysis.

CONCLUSION

Fifteen-year survivors of childhood cancer have excess mortality. More effective treatments must be developed to reduce this excess risk. Fifteen-year relapse-free survivors did not have excess mortality. This group will require continued observation to determine whether excess mortality will become apparent as more events occur.

Vaccinia virus envelope D8L protein binds to cell surface chondroitin sulfate and mediates the adsorption of intracellular mature virions to cells

We previously showed that an envelope A27L protein of intracellular mature virions (IMV) of vaccinia virus binds to cell surface heparan sulfate during virus infection. In the present study we identified another viral envelope protein, D8L, that binds to chondroitin sulfate on cells. Soluble D8L protein interferes with the adsorption of wild-type vaccinia virions to cells, indicating a role in virus entry. To explore the interaction of cell surface glycosaminoglycans and vaccinia virus, we generated mutant viruses from a control virus, WR32-7/Ind14K (A27L(+) D8L(+)) to be defective in expression of either the A27L or the D8L gene (A27L(+) D8L(-) or A27L(-) D8L(+)) or both (A27L(-) D8L(-)). The A27L(+) D8L(+) and A27L(-) D8L(+) mutants grew well in BSC40 cells, consistent with previous observations. However, the IMV titers of A27L(+) D8L(-) and A27L(-) D8L(-) viruses in BSC40 cells were reduced, reaching only 10% of the level for the control virus. The data suggested an important role for D8L protein in WR32-7/Ind14K virus growth in cell cultures. A27L protein, on the other hand, could not complement the functions of D8L protein. The low titers of the A27L(+) D8L(-) and A27L(-) D8L(-) mutant viruses were not due to defects in the morphogenesis of IMV, and the mutant virions demonstrated a brick shape similar to that of the control virions. Furthermore, the infectivities of the A27L(+) D8L(-) and A27L(-) D8L(-) mutant virions were 6 to 10% of that of the A27L(+) D8L(+) control virus. Virion binding assays revealed that A27L(+) D8L(-) and A27L(-) D8L(-) mutant virions bound less well to BSC40 cells, indicating that binding of viral D8L protein to cell surface chondroitin sulfate could be important for vaccinia virus entry.

Sedimentary fluxes of 90Sr, 137Cs, 239,240Pu and 210Pb in the East Sea (Sea of Japan)

Sediment cores collected from the deep basins of the East Sea (Sea of Japan) provide an ongoing and historical record of artificial radionuclides contamination into one of the most highly publicized radioactive waste dumping areas in the world ocean. The depth distributions of 90Sr, 137Cs and 239,240Pu in sediment cores were investigated with the aid of 210Pb-derived sediment accumulation and mixing rates in the deep basins of the East Sea (Sea of Japan). Five box core samples were collected from the northern Yamato Ridge, Korea Plateau, Ulleung and Japan Basins below 1000-m depth. Sediment inventories of 137Cs and 239,240Pu are inversely correlated with water depth and linearly correlated with sediment accumulation rates. The inventories of these nuclides are linearly correlated with the accumulation rates of organic carbon in sediments. The 238Pu/239,240Pu activity ratios in sediments are 0.036 +/- 0.009 suggesting that most of the Pu to the study area is derived from the global fallout. The activity ratios of 239,240Pu/137Cs, and 90Sr/137Cs in bottom sediments are much lower than those of global fallout due to the differences of particle affinity and biological uptake of these nuclides. Sediment inventories of 90Sr and 137Cs constitute < 4% of the anticipated inventories from the global fallout, while those of 239,240Pu constitute 30-150% of the anticipated inventories from the global fallout. The residence time of the dissolved 239,240Pu in the study area is estimated to be 200-400 years based on the sediment inventory and/or sediment accumulation rate, and water column inventory.

Anthropogenic radionuclides in seawater of the Far Eastern Seas

Large quantities of radioactive wastes have been dumped in the Far Eastern Seas by the former Soviet Union and the Russian Federation, and small amounts of radioactive wastes have been dumped by Japan and the Republic of Korea. In order to investigate the concentrations of anthropogenic radionuclides in the nine dumping areas, a second expedition was conducted in 1995 by Japan, the Republic of Korea, the Russian Federation and IAEA, following the first expedition in 1994. The results show that 137Cs, 90Sr and 239 + 240Pu concentrations in surface and bottom waters at dumping areas do not significantly differ from the values observed in background areas, and from historical values. There is no clear effect of possible contamination due to radioactive waste dumping. The concentrations and water column inventories of 137Cs, 90Sr and 239 + 240Pu in the Far Eastern seas are controlled by physical oceanic processes such as horizontal transport and biogeochemical processes such as scavenging.

What is the role of interleukin 10 in polymicrobial sepsis: anti-inflammatory agent or immunosuppressant?

BACKGROUND

Controversy exists concerning the role of interleukin 10 (IL-10) in sepsis. When IL-10 is used in models of endotoxemia, it appears to protect (by anti-inflammatory effects), whereas in models of polymicrobial sepsis it seems to be deleterious (by immunosuppression?). However, little direct evidence for such an immunosuppressive role is available for polymicrobial sepsis. Thus the aim of this study was to determine whether IL-10 contributes to lymphocyte immunosuppression in a model of cecal ligation and puncture (CLP) and whether neutralization of IL-10 has any salutary effects on survival after sepsis.

METHODS

To assess the former, polymicrobial sepsis was induced in male C57BL/6J wild-type (+/+) and C57BL/6J-IL-10 knockout(-/-) mice by CLP. Splenocytes were harvested 24 hours later and stimulated with concanavalin A to assess their proliferative capacity and their ability to release the Th1 lymphokines interleukin 2 and interferon gamma (by enzyme-linked immunosorbent assay, nanograms/millilter). To further verify the immunosuppressive role of IL-10, splenocytes were obtained from male C3H/HeN mice 24 hours after CLP and then stimulated in the presence or absence of anti-IL-10 monoclonal antibody (Mab, 4 micrograms/mL). To assess the in vivo effects of IL-10 neutralization on survival after CLP, C3H/HeN mice (16 per group) were given 250 micrograms of anti-IL-10 Mab (intraperitoneally) either immediately after CLP (before the initiation of the hyperdynamic phase) or 12 hours after CLP (the beginning of the hypodynamic state). Control mice were given nonspecific rat immunoglobulin G.

RESULTS

These data indicate that IL-10 deficiency (-/-) prevents the depression of the proliferative capacity and Th1 lymphokine production after sepsis. Analysis of the interleukin 2-interferon gamma production patterns and proliferative capacity in lymphocytes treated with anti-IL-10 Mab confirmed the role of IL-10 in suppressing lymphocyte responsiveness in CLP. Interestingly, however, only delayed administration (12 hours after CLP) of anti-IL-10 markedly increased survival of mice (Fisher's exact test, P < .05).

CONCLUSION

The results not only illustrate IL-10's role in septic immune dysfunction but document that anti-IL-10 administration beyond the initial proinflammatory hyperdynamic state of polymicrobial sepsis improves survival of animals subjected to sepsis.

Motor perseverative behavior on a line cancellation task

OBJECTIVES

To study the behavioral and neuroanatomic characteristics of perseverative behavior encountered on a target cancellation task in patients with neglect.

METHODS

Motor perseverative behavior during line cancellation task was evaluated retrospectively in 60 patients with left hemispatial neglect from right hemispheric stroke.

RESULTS

More than 30% of the patients (21 of 60) showed perseveration, manifested as either repetitive cancellation of the same target (18/21) or cancelling extra lines created by the patients themselves (3/21). Neglect severity correlated positively with the frequency of perseverative errors. Perseveration was most prominent in the rightmost portion of the array. Anterior lesions or massive lesions involving anterior and posterior regions were more likely to be associated with motor perseveration than were lesions restricted to posterior areas.

CONCLUSIONS

Although the mechanism of motor perseveration remains to be elucidated, our findings suggest that the combination of aberrant approach behaviors associated with frontal lobe injury and an attentional or intentional bias toward the rightsided targets might explain the behavior.

Splenic immune suppression in sepsis: A role for IL-10-induced changes in P38 MAPK signaling

BACKGROUND

Studies have indicated that following the induction of sepsis, there is a late (24 h) generalized suppression of the immune response which is associated with increased anti-inflammatory mediator release (e.g., IL-10). However, the mechanisms by which this occurs are unknown. In this regard, recent studies indicate that p38 mitogen-activated protein kinase (p38 MAPK) may play a central role in transducing the signals from immunosuppressive agents which in turn may alter lymphoid cytokine release. The aim of this study, therefore, was to determine whether the anti-inflammatory mediator IL-10 alters splenocyte IL-2 and IFN-gamma release, as well as the expression and activation of p38 MAPK in septic animals.

MATERIALS AND METHODS

Splenocytes (SPL) (or for some experiments purified T cells) were harvested from mice subjected 24 h earlier to either sepsis by cecal ligation and puncture (CLP) or Sham-CLP and stimulated with 2.5 microg concanavalin A (ConA)/ml in the presence or absence of either monoclonal antibody (Mab) to IL-10 (4 microg/ml) or IgG control. In subsequent studies, sepsis was induced in C57BL/6J and C57BL/6 IL-10 knockout mice, and SPL harvested and stimulated with ConA. SPL cytokine release was measured by ELISA, and the expression and phosphorylation of p38 MAPK were measured by Western analysis.

RESULTS

The results indicate that Th1 cytokine (IL-2, IFN-gamma) release was depressed by sepsis, while p38 MAPK expression and activity were increased in SPL as well as in T-cells. Neutralization of IL-10 by in vitro use of anti-IL-10 Mab and in the IL-10 knockout animal restored the Th1 response and caused a downregulation of p38 MAPK expression and activity after CLP. Thus, IL-10 appears to contribute to the increase in p38 MAPK activity and expression and the corresponding suppression of Th1 response seen in late sepsis.

Increased inducible apoptosis in CD4+ T lymphocytes during polymicrobial sepsis is mediated by Fas ligand and not endotoxin

Recent studies suggest that increased lymphocyte apoptosis (Ao) detected in peripheral blood T cells from burn patients appears to contribute to decreased lymphocyte immunoresponsiveness. However, while it is known that sepsis induces a marked depression in the splenocyte immune response (i.e. decreased interleukin-2, interferon-gamma production and proliferation) in response to the T-cell mitogen concanavalin A (Con A), it is unknown whether this depression is associated with an increase in inducible Ao and if so, which mediators control this process. To assess this, splenocytes were harvested from mice at 24 hr (a period associated with decreased Con A response) after the onset of polymicrobial sepsis [caecal ligation and puncture (CLP)] or sham-CLP (Sham) and then stimulated with 2.5 microg Con A/ml (24 hr). Septic mouse splenocytes stimulated with Con A, while not showing a change in their phenotypic make-up, did exhibit a marked increase in the percentage of splenocyte that were Ao+ which was associated with altered cytokine release. This appears to be due to an increase in the percentage of Ao+ cells in the CD4+ CD8- population and was associated with enhanced Fas antigen expression as well as an increase in mRNA for the Fas-FasL gene family. To determine if the changes in Ao are due to either endotoxin (a product of Gram-negative bacteria seen in CLP mice) or the expression of Fas ligand (FasL; a mediator of activation-induced lymphocyte Ao), a second set of studies examining Con A-inducible Ao was performed with splenocytes harvested from septic endotoxin-tolerant C3H/HeJ and the FasL-deficient C3H/HeJ-Fasl gld mice. The results show that increased splenocyte Ao detected following CLP is due to a FasL-mediated process and not to endotoxin. Thus the inadvertent up-regulation of FasL-mediated splenocyte Ao may contribute to the depression of splenocyte immune responses seen during polymicrobial sepsis.

Frequency of spinocerebellar ataxia types 1,2,3,6,7 and dentatorubral pallidoluysian atrophy mutations in Korean patients with spinocerebellar ataxia

Autosomal dominant cerebellar ataxias (ADCAs) are a heterogeneous group of disorders characterized by degenerative symptoms in the cerebellum, spinal cord, and brain stem. Six different genes have been reported to be associated with ADCA, and the length of trinucleotide repeats of these genes is correlated with the age at onset and severity of symptoms. Although there are strong hereditary effects in these disorders, most of the studies carried out in heterogeneous populations and in small groups obscure the true incidence of these diseases. We examined the frequency of six types of ADCAs in 87 unrelated Korean patients with progressive ataxia and compared the results to the frequencies in other ethnic groups. Spinocerebellar ataxia (SCA) type 2 was the most frequent hereditary ataxia (12.6%) and types 3 and 6 accounted for 4.6% and 6.9% of ataxia patients, respectively. Dentatorubral pallidoluysian atrophy was also found in three patients (3.4%). No instances of SCA types 1 or 7 were detected. These findings show the striking contrast to the white population and a difference from Japanese findings. Our results demonstrate that dentatorubral pallidoluysian atrophy should be included in the differential diagnosis of Korean patients with spinocerebellar ataxia, and that there are strong hereditary effects in patients with ADCAs.

Does Fas ligand or endotoxin contribute to thymic apoptosis during polymicrobial sepsis?

Recent studies have shown that with the onset of sepsis there is an increase in apoptosis (Ao) in the thymus, mediated in part by steroids, which may contribute to a loss of T-cell progenitors, thereby, reducing immune functions. However, reports also suggest that these steroid effects could be mediated by Fas ligand (FasL) and/or by endotoxin (ETX). Thus, our study was to determine: 1) if polymicrobial sepsis (cecal ligation and puncture; CLP) alters thymocyte Fas antigen/receptor (Fas+) expression and 2) if the increase in Ao in septic ETX-sensitive C3H/HeN mice is seen in thymocytes from ETX-tolerant, C3H/HeJ, or the FasL-deficient/ETX-tolerant, C3H/HeJ-FasL(gld), male mouse strains subjected to CLP or sham-CLP (Sham) 12 or 24 h before they were killed. The results of flow cytometric analysis indicated that increased %Ao+ seen in thymocytes of CLP C3H/HeN mice was associated with either no change (12 h) or a decrease in %Fas+ expression at 24 h, although the %Bcl-2+ (an antiapoptotic protein) cells was depressed at both times. Additional studies examining C3H/HeJ or C3H/HeJ-FasL(gld) mice subjected to CLP show that as with the ETX-sensitive mouse, thymocyte Fas and Bcl-2 antigen expression as well as Bcl-2/Bcl-X(L/S) mRNA levels decreased although the %Ao+ increased after CLP in both ETX-tolerant and ETX-tolerant/FasL-deficient mice. Furthermore, if ETX-tolerant/FasL-deficient CLP animals were administered the steroid receptor antagonist RU-38486 (s.c., immediately after CLP) the increase in Ao was markedly attenuated, along with restoration of the percentage of cells expressing Bcl-2 and Fas antigen as well as Bcl-2/Bcl-X(L/S) mRNA levels. Thus, we concluded that increased septic thymocyte Ao is not regulated through either Fas mediated pathway or ETX, but is a result of the release of endogenous steroids possibly acting directly or indirectly on Bcl-2 expression.

Proteasome participates in the alteration of signal transduction in T and B lymphocytes following trauma-hemorrhage

Proteasomes are essential components of the cellular protein degradation machinery. They are nonlysosomal and their participation is critical for (1) the removal of short lived proteins involved in metabolic regulation and cell proliferation, (2) the control of the activities of regulators involved in gene transcription, such as nuclear factor-kappa B (NF-kappa B) and signal transducer and activator of transcription (STAT1), and (3) processing of antigenic peptides for MHC class I presentation. Trauma-hemorrhage induces profound immunosuppression which is characterized by reduced splenocyte proliferation, interleukin (IL)-2 and interferon (IFN)-gamma productive capacity, increased activation of transcription factors NF-kappa B and STAT1 in splenic T lymphocytes, reduced macrophage antigen presentation capacity and inordinate release of proinflammatory cytokines, such as IL-6 and tumor necrosis factor-alpha. Furthermore, it appears that the activity of several regulatory proteins involved in immune function is altered by trauma-hemorrhage. Since proteasomes are involved in regulation and removal of regulatory proteins, we hypothesized that trauma-hemorrhage alters proteasomal activity in splenic lymphocytes. The data showed that activities of 26s proteasome from CD3+CD4+ and CD3+CD8+ splenic T lymphocytes were enhanced following trauma-hemorrhage which was associated with increased expression of NF-kappa B and STAT1. On the other hand, trauma-hemorrhage attenuated the activity of 26s proteasome from splenic B lymphocytes which was restored upon IFN-gamma stimulation and correlated with increased expression of NF-kappa B. These studies indicate a potential role for proteasomes in the regulation of signal transduction in splenic T and B lymphocytes following trauma-hemorrhage, and also suggest them as potential therapeutic targets for attenuation of immune suppression associated with this form of injury.

Relation of plasma homocyst(e)ine to cerebral infarction and cerebral atherosclerosis

BACKGROUND AND PURPOSE

A number of investigations support the theory that the elevated plasma homocyst(e)ine is associated with occlusive vascular disease. The aim of this study is to examine whether moderate hyperhomocyst(e)inemia is an independent risk factor for cerebral infarction. In addition, we examined the association between plasma homocyst(e)ine and the severity of cerebral atherosclerosis.

METHODS

We conducted a hospital-based case-control study with 140 male controls and 78 male patients with nonfatal cerebral infarction, aged between 39 and 82 years. Plasma homocyst(e)ine levels were analyzed in 218 subjects. Fifty-five patients were evaluated for cerebral vascular stenosis by MR angiography.

RESULTS

The mean plasma level of homocyst(e)ine was higher in cases than in controls (11.8+/-5.6 versus 9.6+/-4.1 micromol/L; P=0.002). The proportion of subjects with moderate hyperhomocyst(e)inemia was significantly higher in cases than in controls (16.7% versus 5.0%; P=0.004). Based on the logistic regression model, the odds ratio of the highest 5% of homocyst(e)ine levels in control group was 4.17 (95% confidence interval, 3.71 to 4. 71)(P=0.0001). After additional adjustment for total cholesterol, hypertension, smoking, diabetes, and age, the odds ratio was 1.70 (95% confidence interval, 1.48 to 1.95) (P=0.0001). The plasma homocyst(e)ine levels of patients having vessels with 3 or 2 stenosed sites were significantly higher than those of patients having vessels with 1 stenosed site or normal vessels (14.6+/-1.4, 11.0+/-1.4 versus 7.8+/-1.5, 8.9+/-1.4 micromol/L respectively; P<0. 02). Multiple logistic regression analysis revealed that moderate hyperhomocyst(e)ienemia was significantly associated with the number of stenosed vessels (P=0.001).

CONCLUSIONS

These findings suggest that moderate hyperhomocyst(e)inemia is an independent risk factor for cerebral infarction and may predict the severity of cerebral atherosclerosis in patients with cerebral infarction.

Is Fas ligand or endotoxin responsible for mucosal lymphocyte apoptosis in sepsis?

BACKGROUND

Apoptosis (Ao) is a normal constitutive process that seems to have pathological effects in diseases of immune deficiency and autoimmune disorders, as well as in certain lymphoid tissues during sepsis. Little is known about this process in mucosal lymphoid tissue, such as intestinal intraepithelial lymphocytes (IELs).

OBJECTIVES

To determine whether sepsis induces increased Ao in small intestinal IEL, whether this was associated with functional changes in cytokine gene expression in the IEL, and which mediators control this process and their impact on the survival of the mouse with sepsis.

DESIGN

Male C3H/HeN (endotoxin-sensitive), C3H/HeJ (endotoxin-tolerant), and C3H/HeJ-FasLgld (endotoxin-tolerant/Fas ligand [FasL]-deficient) mice were subjected to sepsis (cecal ligation and puncture [CLP]) and IELs were harvested at 4 (early) or 24 hours (late sepsis). Alterations in the cell phenotype and Ao (TUNEL [terminal deoxynucleotidyl transferase-mediated deoxyuridine 5-triphosphate nick-end labeling] assay) were determined by 3-color flow cytometry. Cytokine gene expression was assessed by multiprobe RNase protection assay.

RESULTS

At 4 hours after CLP, only the frequency of IEL which was CD8+ decreased markedly. By 24 hours after CLP, the number of CD8+ and CD4+ cells decreased while the proportion of double-negative cells showed a marked increase when compared with sham-controls. The percentage of Ao positive in CD8+ and CD4+ double-positive and double-negative cells increased markedly 24 hours after CLP concomitant with a significant (P<.05 vs sham-controls, Mann-Whitney U test) increase in expression of the IL-2, IL-10, and IL-15 gene. These data collectively suggest that sepsis causes lymphocyte activation-induced Ao that may be mediated by FasL. Additional studies were done to determine if the increased Ao was due to either endotoxin or FasL. The results of studies with endotoxin-tolerant C3H/HeJ or FasL-deficient C3H/HeJ-FasLgld mice showed an increase in A,, in CD4+ and CD8+ cells from septic C3H/HeJ but not C3H/HeJ-FasLgld mice. With regard to septic mortality, our results indicated that there was a marked reduction in mortality in C3H/HeJ-FasLgld vs C3H/HeJ mice.

CONCLUSIONS

We conclude that the phenotypic changes associated with increased Ao may be a reflection of localized immune cell activation due to a FasL-mediated process and not endotoxin. Thus, FasL directly and/or indirectly contributes to higher septic mortality.

Cell surface proteoglycans are necessary for A27L protein-mediated cell fusion: identification of the N-terminal region of A27L protein as the glycosaminoglycan-binding domain

We previously showed that vaccinia virus infection of BSC40 cells was blocked by soluble heparin, suggesting that cell surface heparan sulfate mediates vaccinia virus binding (C.-S. Chung, J.-C. Hsiao, Y. -S. Chang, and W. Chang, J. Virol. 72:1577-1585, 1998). In this study, we extended our previous work and demonstrated that soluble A27L protein bound to heparan sulfate on cells and interfered with vaccinia virus infection at a postbinding step. In addition, we investigated the structure of A27L protein that provides for its binding to heparan sulfate on cells. A mutant of A27L protein, named D-A27L, devoid of a cluster of 12 amino acids rich in basic residues, was constructed. In contrast to the soluble A27L protein, purified D-A27L protein was inactive in all of our assays, including binding to heparin in vitro, binding to heparan sulfate on cells, and the ability to block virus infection. These data demonstrated that the N-terminal region acts as a glycosaminoglycan (GAG)-binding domain critical for A27L protein binding to cells. Previously A27L protein was thought to be involved in fusion of virus-infected cells induced by acid treatment. When we investigated whether cell surface GAGs also participate in A27L-dependent fusion, our results indicated that soluble A27L protein blocked cell fusion, whereas D-A27L protein did not. Taken together, the results therefore demonstrated that A27L-mediated cell fusion is triggered by its interaction with cell surface GAGs through the N-terminal domain.