Innate phase production of IFN-γ by memory and effector T cells expressing early activation marker CD69 during infection with Cryptococcus deneoformans in the lungs

Cryptococcus deneoformans is a yeast-type fungus that causes fatal meningoencephalitis in immunocompromised patients and evades phagocytic cell elimination through an escape mechanism. Memory T (Tm) cells play a central role in preventing the reactivation of this fungal pathogen. Among these cells, tissue-resident memory T (TRM) cells quickly respond to locally invaded pathogens. This study analyzes the kinetics of effector T (Teff) cells and Tm cells in the lungs after cryptococcal infection. Emphasis is placed on the kinetics and cytokine expression of TRM cells in the early phase of infection. CD4+ Tm cells exhibited a rapid increase by day 3, peaked at day 7, and then either maintained their levels or exhibited a slight decrease until day 56. In contrast, CD8+ Tm cells reached their peak on day 3 and thereafter decreased up to day 56 post-infection. These Tm cells were predominantly composed of CD69+ TRM cells and CD69+ CD103+ TRM cells. Disruption of the CARD9 gene resulted in reduced accumulation of these TRM cells and diminished interferon (IFN) -γ expression in TRM cells. TRM cells were derived from T cells with T cell receptors non-specific to ovalbumin in OT-II mice during cryptococcal infection. In addition, TRM cells exhibited varied behavior in different tissues. These results underscore the importance of T cells, which produce IFN-γ in the lungs during the early stage of infection, in providing early protection against cryptococcal infection through CARD9 signaling.

Differences in clinicopathological characteristics between lipohypertrophy and localized insulin-derived amyloidosis: A scoping review

Insulin is used as a therapeutic agent in patients with diabetes, and cutaneous lipohypertrophy (LH) and localized insulin-derived amyloidosis (LIDA) are well-known adverse effects associated with insulin injections. The clinical implications, management, assessment methods, and pathological differentiation of LH and LIDA have been recently updated. This review was to update our knowledge of the pathological differentiation, effects of insulin absorption, hypoglycemic events, and recent assessment methods for LH and LIDA. A scoping review was performed according to the Preferred Reporting Items for Systematic Reviews and Meta Analyses extension for Scoping Reviews guidelines. Original studies and case reports in English were also included. PubMed and Scopus databases were searched for keywords to identify papers published up to January 2022. A total of 113 studies were identified through a database search, and 31 were eligible for inclusion in this scoping review. In the 31 studies included in this review, patients with type 2 diabetes had high frequencies of LH and LIDA. LH outcome parameters were assessed using pathological findings and imaging. LIDA is mainly determined by pathological methods, such as hematoxylin and eosin and Congo red staining. Several in vitro and in vivo LIDA models of LIDA have been developed. These results suggest that pathological analysis is required to identify LH and LIDA. It is important to consider LIDA, as it likely influences insulin adsorption and glycemic control. Although several studies have evaluated the LIDA process, little is known about the mechanisms underlying the development of adverse effects associated with insulin injections.

CARD9-mediated macrophage responses and collagen fiber capsule formation caused by textured-type breast implants

BACKGROUND

An increasing number of women are undergoing breast implantation for cosmetic purposes and for reconstructive purposes after breast excision. The surface morphology of the breast implant is one of the key factors associated with the induction of capsule contraction. The effect of surface morphology on the inflammatory response following implant insertion remains unclear, however. This study conducted comparative analyses to determine the effect of the textured and smooth surface morphology of silicone sheets.

METHODS

Each type of silicone sheet was inserted into the subcutaneous pocket below the panniculus carnosus in C57BL/6 mice and mice with genetic disruption of CARD9, Dectin-1, Dectin-2, or Mincle. We also analyzed the collagen fiber capsule thickness, histological findings, and macrophage inflammatory response, including TGF-β synthesis.

RESULTS

We found that textured surface morphology contributed to the formation of collagen fiber capsules and the accumulation of fibroblasts and myofibroblasts, and was accompanied by the accumulation of TGF-β-expressing macrophages and foreign-body giant cells. CARD9 deficiency attenuated collagen fiber capsule formation, macrophage responses, and TGF-β synthesis, although the responsible C-type lectin receptors (CLRs) remain to be clarified.

CONCLUSIONS

These results suggest that CARD9 may have a strong impact on silicone sheet insertion through the regulation of macrophage responses.

Cutaneous wound healing promoted by topical administration of heat-killed Lactobacillus plantarum KB131 and possible contribution of CARD9-mediated signaling

Optimal conditions for wound healing require a smooth transition from the early stage of inflammation to proliferation, and during this time alternatively activated (M2) macrophages play a central role. Recently, heat-killed lactic acid bacteria (LAB), such as Lactobacillus plantarum (L. plantarum) have been reported as possible modulators affecting the immune responses in wound healing. However, how signaling molecules regulate this process after the administration of heat-killed LAB remains unclear. In this study, we examined the effect of heat-killed L. plantarum KB131 (KB131) administration on wound healing and the contribution of CARD9, which is an essential signaling adaptor molecule for NF-kB activation upon triggering through C-type lectin receptors, in the effects of this bacterium. We analyzed wound closure, histological findings, and inflammatory responses. We found that administration of KB131 accelerated wound closure, re-epithelialization, granulation area, CD31-positive vessels, and α-SMA-positive myofibroblast accumulated area, as well as the local infiltration of leukocytes. In particular, M2 macrophages were increased, in parallel with CCL5 synthesis. The acceleration of wound healing responses by KB131 was canceled in CARD9-knockout mice. These results indicate that the topical administration of KB131 accelerates wound healing, accompanying increased M2 macrophages, which suggests that CARD9 may be involved in these responses.

Deficiency of lung-specific claudin-18 leads to aggravated infection with Cryptococcus deneoformans through dysregulation of the microenvironment in lungs

Cryptococcus deneoformans is an opportunistic fungal pathogen that infects the lungs via airborne transmission and frequently causes fatal meningoencephalitis. Claudins (Cldns), a family of proteins with 27 members found in mammals, form the tight junctions within epithelial cell sheets. Cldn-4 and 18 are highly expressed in airway tissues, yet the roles of these claudins in respiratory infections have not been clarified. In the present study, we analyzed the roles of Cldn-4 and lung-specific Cldn-18 (luCldn-18) in host defense against C. deneoformans infection. luCldn-18-deficient mice exhibited increased susceptibility to pulmonary infection, while Cldn-4-deficient mice had normal fungal clearance. In luCldn-18-deficient mice, production of cytokines including IFN-γ was significantly decreased compared to wild-type mice, although infiltration of inflammatory cells including CD4⁺ T cells into the alveolar space was significantly increased. In addition, luCldn-18 deficiency led to high K⁺ ion concentrations in bronchoalveolar lavage fluids and also to alveolus acidification. The fungal replication was significantly enhanced both in acidic culture conditions and in the alveolar spaces of luCldn-18-deficient mice, compared with physiological pH conditions and those of wild-type mice, respectively. These results suggest that luCldn-18 may affect the clinical course of cryptococcal infection indirectly through dysregulation of the alveolar space microenvironment.

Topical Administration of Heat-Killed Enterococcus faecalis Strain KH2 Promotes Re-Epithelialization and Granulation Tissue Formation during Skin Wound-Healing

Lactic acid bacteria (LAB) are known to have beneficial effects on immune responses when they are orally administered as bacterial products. Although the beneficial effects of LAB have been reported for the genera Lactobacillus and Lactococcus, little has been uncovered on the effects of the genus Enterococcus on skin wound-healing. In this study, we aimed to clarify the effect of heat-killed Enterococcus faecalis KH2 (heat-killed KH2) strain on the wound-healing process and to evaluate the therapeutic potential in chronic skin wounds. We analyzed percent wound closure, re-epithelialization, and granulation area, and cytokine and growth factor production. We found that heat-killed KH2 contributed to the acceleration of re-epithelialization and the formation of granulation tissue by inducing tumor necrosis factor-α, interleukin-6, basic fibroblast growth factor, transforming growth factor (TGF)-β1, and vascular endothelial growth factor production. In addition, heat-killed KH2 also improved wound closure, which was accompanied by the increased production of TGF-β1 in diabetic mice. Topical administration of heat-killed KH2 might have therapeutic potential for the treatment of chronic skin wounds in diabetes mellitus. In the present study, we concluded that heat-killed KH2 promoted skin wound-healing through the formation of granulation tissues and the production of inflammatory cytokines and growth factors.

Contribution of Invariant Natural Killer T Cells to the Clearance of Pseudomonas aeruginosa from Skin Wounds

Chronic infections are considered one of the most severe problems in skin wounds, and bacteria are present in over 90% of chronic wounds. Pseudomonas aeruginosa is frequently isolated from chronic wounds and is thought to be a cause of delayed wound healing. Invariant natural killer T (iNKT) cells, unique lymphocytes with a potent regulatory ability in various inflammatory responses, accelerate the wound healing process. In the present study, we investigated the contribution of iNKT cells in the host defense against P. aeruginosa inoculation at the wound sites. We analyzed the re-epithelialization, bacterial load, accumulation of leukocytes, and production of cytokines and antimicrobial peptides. In iNKT cell-deficient (Jα18KO) mice, re-epithelialization was significantly decreased, and the number of live colonies was significantly increased, when compared with those in wild-type (WT) mice on day 7. IL-17A, and IL-22 production was significantly lower in Jα18KO mice than in WT mice on day 5. Furthermore, the administration of α-galactosylceramide (α-GalCer), a specific activator of iNKT cells, led to enhanced host protection, as shown by reduced bacterial load, and to increased production of IL-22, IL-23, and S100A9 compared that of with WT mice. These results suggest that iNKT cells promote P. aeruginosa clearance during skin wound healing.

Dectin-2-mediated initiation of immune responses caused by influenza virus hemagglutinin

Antigen-presenting cells express pattern recognition receptors (PRRs), which sense pathogen-associated molecular patterns from microorganisms and lead to the induction of inflammatory responses. C-type lectin receptors (CLRs), the representative PRRs, bind to microbial polysaccharides, among which Dectin-2 and Mincle recognize mannose-containing polysaccharides. Because influenza virus (IFV) hemagglutinin (HA) is rich in mannose polysaccharides, Dectin-2 or Mincle may contribute to the recognition of HA. In this study, we addressed the possible involvement of Dectin-2 and Mincle in the viral recognition and the initiation of cytokine production. Interleukin (IL)-12p40 and IL-6 production by bone marrow-derived dendritic cells (BM-DCs) upon stimulation with HA was significantly reduced in Dectin-2 knockout (KO) mice compared to wild-type (WT) mice whereas there was no difference between WT mice and Mincle KO mice. BM-DCs that were treated with Syk inhibitor resulted in a significant reduction of cytokine production upon stimulation with HA. The treatment of BM-DCs with methyl-α-D-mannopyranoside (ManP) also led to a significant reduction in cytokine production by BM-DCs that were stimulated with HA, except for the A/H1N1pdm09 subtype. IL-12p40 and IL-6 synthesis by BM-DCs was completely diminished upon stimulation with HA treated with concanavalin A (ConA)-bound sepharose beads. Finally, GFP expression was detected in reporter cells that were transfected with the Dectin-2 gene, but not with the Mincle gene, when stimulated with HA derived from the A/H3N2 subtype. These data suggested that Dectin-2 may be a key molecule as the sensor for IFV to initiate the immune response and regulate the pathogenesis of IFV infection.

Novel Toll-Like Receptor 9 Agonist Derived from Cryptococcus neoformans Attenuates Allergic Inflammation Leading to Asthma Onset in Mice

INTRODUCTION

The enhanced type 2 helper (Th2) immune response is responsible for the pathogenesis of allergic asthma. To suppress the enhanced Th2 immune response, activation of the Th1 immune response has been an alternative strategy for anti-asthma therapy. In this context, effective Th1-inducing adjuvants that inhibit the development of allergic asthma but do not flare the side effects of the primary agent are required in clinical treatment and preventive medicine.

OBJECTIVE

In this study, we aimed to determine the regulation of the Th2 type immune response in asthma by a novel immunostimulatory oligodeoxynucleotide (ODN) derived from Cryptococcus neoformans, termed ODN112, which contains a cytosine-guanine (CG) sequence but not canonical CpG motifs.

METHODS

Using an ovalbumin-induced asthma mouse model, we assessed the effect of ODN112 on prototypical asthma-related features in the lung and on the Th1/Th2 profile in the lymph nodes and lung of mice treated with ODN112 during sensitization.

RESULTS AND CONCLUSION

ODN112 treatment attenuated asthma features in mice. In the bronchial lymph nodes of the lungs and in the spleen, ODN112 increased interferon-γ production and attenuated Th2 recall responses. In dendritic cells (DCs) after allergen sensitization, ODN112 enhanced cluster of differentiation (CD) 40 and CD80 expression but did not alter CD86 expression. Interleukin-12p40 production from DCs was also increased in a Th2-polarizing condition. Our results suggest that ODN112 is a potential Th1-inducing adjuvant during Th2 cell differentiation in the sensitization phase.

Production of IL-17A at Innate Immune Phase Leads to Decreased Th1 Immune Response and Attenuated Host Defense against Infection with Cryptococcus deneoformans

IL-17A is a proinflammatory cytokine produced by many types of innate immune cells and Th17 cells and is involved in the elimination of extracellularly growing microorganisms, yet the role of this cytokine in the host defense against intracellularly growing microorganisms is not well known. Cryptococcus deneoformans is an opportunistic intracellular growth fungal pathogen that frequently causes fatal meningoencephalitis in patients with impaired immune responses. In the current study, we analyzed the role of IL-17A in the host defense against C. deneoformans infection. IL-17A was quickly produced by γδT cells at an innate immune phase in infected lungs. In IL-17A gene-disrupted mice, clearance of this fungal pathogen and the host immune response mediated by Th1 cells were significantly accelerated in infected lungs compared with wild-type mice. Similarly, killing of this fungus and production of inducible NO synthase and TNF-α were significantly enhanced in IL-17A gene-disrupted mice. In addition, elimination of this fungal pathogen, Th1 response, and expression of IL-12Rβ2 and IFN-γ in NK and NKT cells were significantly suppressed by treatment with rIL-17A. The production of IL-12p40 and TNF-α from bone marrow-derived dendritic cells stimulated with C. deneoformans was significantly suppressed by rIL-17A. In addition, rIL-17A attenuated Th1 cell differentiation in splenocytes from transgenic mice highly expressing TCR for mannoprotein 98, a cryptococcal Ag, upon stimulation with recombinant mannoprotein 98. These data suggest that IL-17A may be involved in the negative regulation of the local host defense against C. deneoformans infection through suppression of the Th1 response.

Distinct Roles for Dectin-1 and Dectin-2 in Skin Wound Healing and Neutrophilic Inflammatory Responses

C-type lectin receptors recognize microbial polysaccharides. The C-type lectin receptors such as dendritic cell-associated C-type lectin (Dectin)-1 and Dectin-2, which are triggered by β-glucan and α-mannan, respectively, contribute to upregulation of the inflammatory response. Recently, we demonstrated that activation of the Dectin-2 signal delayed wound healing; in previous studies, triggering the Dectin-1 signal promoted this response. However, the precise roles of these C-type lectin receptors in skin wound healing remain unclear. This study was conducted to determine the roles of Dectin-1 and Dectin-2 in skin wound healing, with a particular focus on the kinetics of neutrophilic inflammatory response. Full-thickness wounds were created on the backs of C57BL/6 mice, and the effects of Dectin-1 or Dectin-2 deficiency and those of β-glucan or α-mannan administration were examined. We also analyzed wound closure, histological findings, and neutrophilic inflammatory response, including neutrophil extracellular trap formation at the wound sites. We found that Dectin-1 contributed to the acceleration of wound healing by inducing early-phase neutrophil accumulation, whereas Dectin-2 was involved in prolonged neutrophilic responses and neutrophil extracellular trap formation, leading to delayed wound healing. Dectin-2 deficiency also improved collagen deposition and TGF-β1 expression. These results suggest that Dectin-1 and Dectin-2 have different roles in wound healing through their different effects on the neutrophilic response.

Defect of Interferon γ Leads to Impaired Wound Healing through Prolonged Neutrophilic Inflammatory Response and Enhanced MMP-2 Activation

Interferon (IFN)-γ is mainly secreted by CD4+ T helper 1 (Th1), natural killer (NK) and NKT cells after skin injury. Although IFN-γ is well known regarding its inhibitory effects on collagen synthesis by fibroblasts in vitro, information is limited regarding its role in wound healing in vivo. In the present study, we analyzed how the defect of IFN-γ affects wound healing. Full-thickness wounds were created on the backs of wild type (WT) C57BL/6 and IFN-γ-deficient (KO) mice. We analyzed the percent wound closure, wound breaking strength, accumulation of leukocytes, and expression levels of COL1A1, COL3A1, and matrix metalloproteinases (MMPs). IFN-γKO mice exhibited significant attenuation in wound closure on Day 10 and wound breaking strength on Day 14 after wound creation, characteristics that are associated with prolonged neutrophil accumulation. Expression levels of COL1A1 and COL3A1 mRNA were lower in IFN-γKO than in WT mice, whereas expression levels of MMP-2 (gelatinase) mRNA were significantly greater in IFN-γKO than in WT mice. Moreover, under neutropenic conditions created with anti-Gr-1 monoclonal antibodies, wound closure in IFN-γKO mice was recovered through low MMP-2 expression levels. These results suggest that IFN-γ may be involved in the proliferation and maturation stages of wound healing through the regulation of neutrophilic inflammatory responses.

Dectin-2-Mediated Signaling Leads to Delayed Skin Wound Healing through Enhanced Neutrophilic Inflammatory Response and Neutrophil Extracellular Trap Formation

Dendritic cell-associated C-type lectin-2 (i.e., dectin-2) recognizes fungal polysaccharides, including α-mannan. Dectin-2-mediated recognition of fungi, such as Candida albicans, leads to NF-κB activation, which induces production of inflammatory cytokines. However, the role of dectin-2 in skin wound healing remains unclear. In this study, we sought to determine how dectin-2 deficiency and the administration of α-mannan affected the wound healing process. Full-thickness wounds were created on the backs of wild type C57BL/6 and dectin-2-deficient mice. We analyzed wound closure, histological findings, and re-epithelialization. We also examined the neutrophilic inflammatory responses and neutrophil extracellular trap (NET)-osis at the wound sites after administration of α-mannan. The percent wound closure and re-epithelialization was significantly accelerated in dectin-2-knockout mice compared with wild-type mice on days 3 and 5 after wounding. In contrast, administration of α-mannan delayed wound closure in wild-type mice, and these responses were canceled in dectin-2-knockout mice. Furthermore, mice administered α-mannan, neutrophil infiltration was prolonged, and the expression of citrullinated histone, an indicator of NETosis, at the wound sites was accelerated. Administration of a neutrophil elastase inhibitor significantly improved the delayed wound healing caused by α-mannan. These results suggest that dectin-2 may have a deep impact on the skin wound healing process through regulation of neutrophilic responses.

Invariant NKT cells promote skin wound healing by preventing a prolonged neutrophilic inflammatory response

The wound-healing process consists of the inflammation, proliferation, and remodeling phases. In chronic wounds, the inflammation phase is prolonged with persistent neutrophil infiltration. The inflammatory response is critically regulated by cytokines and chemokines that are secreted from various immune cells. Recently, we showed that skin wound healing was delayed and the healing process was impaired under conditions lacking invariant natural killer T (iNKT) cells, an innate immune lymphocyte with potent immuno-regulatory activity. In the present study, we investigated the effect of iNKT cell deficiency on the neutrophilic inflammatory response during the wound healing process. Neutrophil infiltration was prolonged in wound tissue in mice genetically lacking iNKT cells (Jα18KO mice) than in wild-type (WT) control mice on days 1 and 3 after wounding. MIP-2, KC, and IL-17A were produced at a significantly higher level in Jα18KO mice than in WT mice. In addition, neutrophil apoptosis was significantly reduced in the wound tissue in Jα18KO mice than in WT mice. Treatment with anti-IL-17A mAb, anti-Gr-1 mAb, or neutrophil elastase inhibitor reversed the impaired wound healing in Jα18KO mice. These results suggest that iNKT cells may promote the wound healing process through preventing the prolonged inflammatory response mediated by neutrophils.

Contribution of CARD9-mediated signalling to wound healing in skin

The inflammatory response after skin injury involves the secretion of a variety of cytokines and growth factors that are necessary for tissue repair. Caspase recruitment domain-containing protein 9 (CARD9) is an essential signalling adaptor molecule for NF-κB activation upon triggering through C-type lectin receptors (CLRs), which are expressed in macrophages and dendritic cells. However, the role of CARD9 in inflammatory responses at the wound site has not been elucidated. In this study, we analysed the role of CARD9 in the healing process of skin wounds. Wounds were created on the backs of wild-type (WT) C57BL/6 mice and CARD9 gene-disrupted (knockout [KO]) mice. We analysed per cent wound closure, and the wound tissues were harvested for analysis of leucocyte accumulation and cytokine and chemokine expressions. CARD9KO mice exhibited significant attenuation of wound closure compared with WT mice on days 5, 7 and 10 postwounding, which was associated with decreased macrophage accumulation and reduced TNF-α, IL-1β, CCL3 and CCL4 expressions. These results suggest that CARD9 may be involved in the wound-healing process through the regulation of macrophage-mediated inflammatory responses.

IL-17A promotes neutrophilic inflammation and disturbs acute wound healing in skin

In the wound healing process, neutrophils are the first inflammatory cells to move to the wound tissues. They sterilize wounds by killing microbes, and they stimulate other immune cells to protect the host from infection. In contrast, neutrophil-derived proteases cause damage to host tissues, so neutrophils play dual opposite roles in wound healing. Interleukin-17A (IL-17A) is a proinflammatory cytokine that promotes the recruitment of these cells. The role of this cytokine in the wound healing process is not fully clarified. In the present study, therefore, we examined how defect in IL-17A production affected the wound healing in skin. IL-17A-knockout (KO) mice showed promoted wound closure, myofibroblast differentiation and collagen deposition and decreased the neutrophil accumulation compared with wild-type (WT) mice. In contrast, the administration of recombinant IL-17A led to delayed wound closure, low collagen deposition and accelerated neutrophilic accumulation. In addition, the treatment of IL-17A-administered mice with a neutrophil elastase inhibitor improved the wound repair to the same level as that of WT mice. These results indicated that IL-17A hampered the wound healing process and suggested that neutrophilic inflammation caused by IL-17A may be associated with impaired wound healing in skin.

Contribution of Invariant Natural Killer T Cells to Skin Wound Healing

In the present study, we determined the contribution of invariant natural killer T (iNKT) cells to the skin wound healing process. In iNKT cell-deficient (Jα18KO) mice lacking iNKT cells, wound closure was significantly delayed compared with wild-type mice. Collagen deposition, expression of α-smooth muscle actin and CD31, and wound breaking strength were significantly attenuated in Jα18KO mice. The adoptive transfer of liver mononuclear cells from wild-type but not from Jα18KO or interferon (IFN)-γ gene-disrupted (IFN-γKO) mice resulted in the reversal of this impaired wound healing in Jα18KO mice. IFN-γ expression was induced in the wounded tissues, which was significantly decreased at 6, 12, and 24 hours, but increased on day 3 after wounding in Jα18KO mice. The main source of the late-phase IFN-γ production in Jα18KO mice were neutrophils rather than NK cells and T cells. Administration of α-galactosylceramide, an activator of iNKT cells, resulted in the acceleration of wound healing on day 3 in wild-type mice. This effect was not observed in IFN-γKO mice. These results indicate that iNKT cells play important roles in wound healing. The iNKT cell-induced IFN-γ production may regulate the wound healing process in the early phase.

Promotion of acute-phase skin wound healing by Pseudomonas aeruginosa C4 -HSL

A Pseudomonas aeruginosa quorum-sensing system, which produces N-(3-oxododecanoyl)-l-homoserine lactone (3-oxo-C₁₂ -HSL) and N-butanoyl-l-homoserine lactone (C₄ -HSL), regulates the virulence factors. In our previous study, 3-oxo-C₁₂ -HSL, encoded by lasI gene, was shown to promote wound healing. However, the effect of C₄ -HSL, encoded by rhlI gene, remains to be elucidated. We addressed the effect of C₄ -HSL on wounds in P. aeruginosa infection. Wounds were created on the backs of Sprague-Dawley SD rats, and P. aeruginosa PAO1 (PAO1) or its rhlI deletion mutant (ΔrhlI) or lasI deletion mutant (ΔlasI) was inoculated onto the wound. Rats were injected intraperitoneally with anti-C₄ -HSL antiserum or treated with C₄ -HSL at the wound surface. PAO1 inoculation led to significant acceleration of wound healing, which was associated with neutrophil infiltration and TNF-α synthesis. These responses were reversed, except for TNF-α production, when ΔrhlI was inoculated instead of PAO1 or when rats were co-treated with PAO1 and anti-C₄ -HSL antiserum. In contrast, the healing process and neutrophil infiltration, but not TNF-α synthesis, were accelerated when C₄ -HSL was administered in the absence of PAO1. This acceleration was not affected by anti-TNF-α antibody. These results suggest that C₄ -HSL may be involved in the acceleration of acute wound healing in P. aeruginosa infection by modifying the neutrophilic inflammation.

Free-flight measurement technique in the free-piston high-enthalpy shock tunnel

A novel multi-component force-measurement technique has been developed and implemented at the impulse facility JAXA-HIEST, in which the test model is completely unrestrained during the test and thus experiences free-flight conditions for a period on the order of milliseconds. Advantages over conventional free-flight techniques include the complete absence of aerodynamic interference from a model support system and less variation in model position and attitude during the test itself. A miniature on-board data recorder, which was a key technology for this technique, was also developed in order to acquire and store the measured data. The technique was demonstrated in a HIEST wind-tunnel test campaign in which three-component aerodynamic force measurement was performed on a blunted cone of length 316 mm, total mass 19.75 kg, and moment of inertia 0.152 kgm(2). During the test campaign, axial force, normal forces, and pitching moment coefficients were obtained at angles of attack from 14° to 32° under two conditions: H0 = 4 MJ/kg, P0 = 14 MPa; and H0 = 16 MJ/kg, P0 = 16 MPa. For the first, low-enthalpy condition, the test flow was considered a perfect gas; measurements were thus directly compared with those obtained in a conventional blow-down wind tunnel (JAXA-HWT2) to evaluate the accuracy of the technique. The second test condition was a high-enthalpy condition in which 85% of the oxygen molecules were expected to be dissociated; high-temperature real-gas effects were therefore evaluated by comparison with results obtained in perfect-gas conditions. The precision of the present measurements was evaluated through an uncertainty analysis, which showed the aerodynamic coefficients in the HIEST low enthalpy test agreeing well with those of JAXA-HWT2. The pitching-moment coefficient, however, showed significant differences between low- and high-enthalpy tests. These differences are thought to result from high-temperature real-gas effects.

Low-energy extracorporeal shock wave therapy enhances skin wound healing in diabetic mice: a critical role of endothelial nitric oxide synthase

Low-energy extracorporeal shock wave (LE-ESW) treatment has been shown to accelerate wound repair; however, the mechanisms of treatment remain unclear. In the present study, we addressed the role of endothelial nitric oxide synthase (eNOS). A single LE-ESW treatment accelerated the healing of wounds in diabetic mice caused by the injection of streptozotocin. This accelerated healing was accompanied by the increased expression of eNOS and vascular endothelial growth factor (VEGF) and the generation of new vessels at the wound tissues. These results raised the possibility that eNOS may be involved in the beneficial effects of LE-ESW treatment. To address this possibility, we compared the effects of this treatment between mice with a genetic disruption of eNOS knockout (eNOS-KO mice) and wild-type (WT) control mice. Interestingly, the LE-ESW-induced acceleration of wound closure and the increase in VEGF expression and neovascularization was significantly attenuated in eNOS-KO mice compared with WT mice. Considered collectively, these results showed that eNOS was induced at the wound tissues by LE-ESW treatment and played a critical role in the therapeutic effects of this treatment by accelerating the wound healing by promoting VEGF expression and neovascularization.

Skin wound healing and cytokine response promoted by a quorum-sensing molecule from Pseudomonas aeruginosa (55.16)

Quorum-sensing systems regulate virulence factors in Pseudomonas aeruginosa, which produces two autoinducers, N-3-oxododecanoyl or N-butanoyl-L-homoserine lactone (3-oxo-C12- or C4-HSL, respectively). Production of each HSL is regulated by the lasI or rhlI gene. Recently, HSLs are considered to play important roles in modulating immune responses. In this study, we addressed the effect of HSLs on the wound healing in skin. Wounds were created on the back of SD rats. P. aeruginosa PAO1 and its lasI or rhlI-deletion mutant (ΔlasI or ΔrhlI) were inoculated at the wound surface. Rats were injected intraperitoneally with anti-3-oxo-C12-HSL or -C4-HSL antiserum or administered each HSL at the wound surface. The wound tissues were harvested for analysis of re-epithelialization, accumulation of neutrophils and synthesis of TNF-α. Inoculation with PAO1 significantly accelerated the healing process, as evaluated by re-epithelialization, on day 3 post-wounding, which was associated with the local infiltration of neutrophils and synthesis of TNF-α. These responses were not observed when inoculated with ΔlasI or ΔrhlI in place of PAO1 and cancelled when co-treated with these anti HSL antisera, respectively, but not with control rabbit serum. By contrast, administration of either HSL in the absence of PAO1 significantly accelerated the re-epithelialization. These results suggest that 3-oxo-C12-HSL and C4-HSL may be deeply involved in the skin wound healing during P. aeruginosa infection.

Wound healing in skin promoted by inoculation with Pseudomonas aeruginosa PAO1: The critical role of tumor necrosis factor-α secreted from infiltrating neutrophils

Wound healing is promoted by the presence of replicating microorganisms adhering to the wounded tissue, but the precise mechanism is not fully understood. In the present study, using a rat model with full-thickness dermal wounds, we examined the effect of Pseudomonas aeruginosa inoculation on wound healing and the role of neutrophils infiltrating the wound site. Within 3 days, inoculation with this bacterium had accelerated re-epithelialization, epidermal cell proliferation, and neo-vascularization, as well as the local infiltration of neutrophils, which reached a peak at 24 hours. Tumor necrosis factor (TNF)-α was detected in the wound tissues on the mRNA and protein levels within 24 hours. Flow cytometry and immunohistochemical analyses detected higher levels of TNF-α in the infiltrating neutrophils in rats inoculated with P. aeruginosa than in uninoculated rats. Neutropenic rats treated with anti-neutrophil mAb or cyclophosphamide exhibited significant attenuation in re-epithelialization, epidermal cell proliferation, neo-vascularization, and TNF-α synthesis compared with control; administration of TNF-α reversed these attenuations. These wound-healing responses were decelerated in rats treated with anti-TNF-α mAb, as was the infiltration of neutrophils. These results indicate that inoculation with P. aeruginosa promotes wound healing by inducing the infiltration of neutrophils, which play a critical role as a major source of TNF-α.

An Early MRI Change following Reversible Hypoxic Brain Injury

We describe a patient who suffered reversible hypoxic brain injury. The initial MRI taken 3.5 hours after asphyxiation showed an abnormal lesion on DWI, but he recovered completely from coma. The presence of cytotoxic edema in the acute stage may not necessarily indicate a poor prognosis.

Pediatric and adult forms of type I autoimmune hepatitis in Argentina: evidence for differential genetic predisposition

The aim of this study was to compare major histocompatibility complex (MHC) class II susceptibility to type 1 autoimmune hepatitis (AH) between children and adults of the same ethnic group. HLA-DRB1, HLA-DRB3, HLA-DQA1, and HLA-DQB1 gene subtypes were examined by high resolution oligonucleotide typing in 122 pediatric (PAH) and 84 adult (AAH) patients and in 208 controls. In children, HLA-DRB1*1301 was the primary susceptibility allele (66.4% patients vs. 10.6% controls, relative risk [RR] = 16.3, Pc < 10(-24)) whereas HLA-DRB1*1302, which differs from HLA-DRB1*1301 by only 1 amino acid, appeared to be protective. The exclusion of individuals with HLA-DRB1*1301 from control and pediatric patients allowed us to find a secondary association of PAH with HLA-DRB1*0301. Possession of HLA-DRB1*1301, however, was associated with a lower therapeutic response rate. Analysis of peptide binding pocket residues indicated that Tyr 10, Ser 11, Ser 13, and Val 86 in the class II beta chain were present in 85% of patients compared with 37% of controls, suggesting that a high proportion of AH susceptibility is attributable to these residues (etiologic fraction [EF] = 76%). In contrast to the class II associations in children, AAH was associated with HLA-DRB1*0405 (RR = 10.4, Pc <.005) but not with HLA-DRB1*1301 or HLA-DRB1*0301. In addition, HLA-DR4 with the class I gene, HLA-A11, appeared synergistic in predisposing AAH patients to develop extra-hepatic autoimmune (AI) manifestations (odds ratio [OR] = 104.9, Pc < 10(-4)). Concomitant differences in autoantibody profiles were also observed in PAH versus AAH: smooth muscle antibodies (SMA) were most prevalent in PAH but antinuclear antibodies were most prevalent in AAH (P =.003). This study therefore reveals that different HLA-DRB1 allotypes confer susceptibility to AH in children and adults and raises the possibility that PAH and AAH may be triggered by different factors.

Prognostic value of hepatic venous pressure gradient measurements in alcoholic cirrhosis: a 10-year prospective study

BACKGROUND & AIMS

Different parameters are considered predictors of bleeding and death in alcoholic cirrhosis. The aim of this study was to establish the prognostic value of a prospective and sequential evaluation of portal pressure, variceal size, and Pugh's score in portal-hypertensive patients with alcoholic cirrhosis but no previous bleeding.

METHODS

Thirty patients were evaluated for 42 +/- 5 months (median, 39 months). After baseline studies, 30 patients underwent an additional evaluation (follow-up 1; median, 10 months), 20 patients a second evaluation (follow-up 2; median, 25 months), and 13 patients a third evaluation (follow-up 3; median, 45 months). No prophylactic treatment for bleeding was given. End points were bleeding and/or death.

RESULTS

Seventeen patients died, and 10 patients bled. At follow-up 1, portal pressure decreased both in survivors and nonbleeders (from 18.7 +/- 1.0 to 15.2 +/- 1.3 mm Hg [P < 0.01] and from 18.9 +/- 0.8 to 16.5 +/- 1.0 mm Hg [P < 0.05], respectively). On multivariate analysis (Cox model), portal pressure at follow-up 1 had the best prognostic and independent value for both bleeding and survival. Subsequent studies showed similar trends.

CONCLUSIONS

Measurements of portal pressure provide unique prognostic information for predicting portal hypertensive-related bleeding and mortality in patients with alcoholic cirrhosis.

Reactive astrocytes in acute stage after experimental brain injury: relationship to extravasated plasma protein and expression of heat shock protein

It is well known that an astrocytic response occurs after brain damage; however, the mechanisms initiating this acute astrocytic response remain unclear. In this study, we examined the immunolocalization of glial fibrillary acidic protein (GFAP) to investigate the astrocytic response within 72 h after injury. Further, we related these results to the distribution of extravasated plasma protein and the expression of stress protein. Adult male Wistar rats were subjected to a lateral fluid percussion brain injury. Animals were sacrificed at 1, 6, 24, and 72 h postinjury. Each brain section was immunostained for GFAP, extravasated albumin, and heat shock protein (HSP 72). Immunoreactive astrocytes, extravasated albumin, and HSP 72 positive cells were evaluated by light microscopy. Reactive astrocytes were defined by the presence of increased immunoreactivity to anti-GFAP. By 6 h, the presence of reactive astrocytes was restricted to the impact site and the hemorrhagic external capsule. At 24 h, reactive astrocytes were identified in the entire injured hemisphere. By 72 h, the immunoreactive astrocytes were more pronounced than at 24 h. At 1 h, extravasated albumin was found at the impact site, the hemorrhagic external capsule, the parasagittal cortex, hippocampus, thalamus, and midbrain. By 72 h, the immunostaining of albumin was more widely distributed. HSP 72 immunoreactive glia were detected only at the impact site and the hemorrhagic external capsule. In summary, the distribution of reactive astrocytes at 6 h was associated with HSP 72-positive glia rather than the extravasation of albumin. In contrast, the distribution of reactive astrocytes at 24 and 72 h paralleled that of extravasated albumin. These results suggest that the initial response of astrocytes is correlated to glial stress and/or injury and that humoral factors play a role in the subsequent responses.

The blood-brain barrier disruption to circulating proteins in the early period after fluid percussion brain injury in rats

Breakdown of the blood-brain barrier (BBB) immediately after traumatic brain injury is not clearly understood. In the present study we focused on the integrity of the BBB to circulating proteins within the first hour after injury. For this purpose, vascular permeability to endogenous albumin and to the exogenous protein tracer horseradish peroxidase (HRP) was examined after a lateral fluid percussion brain injury in rats. Albumin was immunolocalized in brain sections at 3 and 60 min after impact. This distribution was compared with the histochemical localization of HRP given before impact at the same time points. In a separate experiment HRP was given prior to sacrifice to determine the time course for the barrier disruption. Permeability to this protein was assessed at 13, 30, and 60 min after impact. Prominent extravasation of albumin occurred within 3 min of injury and was present in multiple foci within the injured hemisphere. At 60 min the extravasated albumin was present in the same sites, where it was widely distributed. Throughout the related brain parenchyma, little difference was found between the extravascular distribution of albumin and HRP. In the delayed administration paradigm breakdown of the BBB was noted in the impact site, hemorrhagic site in the deep cortical layer, hippocampus, thalamus, and midbrain at 13 min after injury. This injured barrier was restored in most regions by 30 min. However, the impact site and hemorrhagic site remained permeable up to 60 min postinjury. In addition, newly developed barrier disruption to HRP occurred in the parasagittal cortex at 30 and 60 min. In conclusion, widespread breakdown of the BBB to circulating proteins occurred within a few minutes after traumatic brain injury. The time course for this barrier disruption is characterized by three different patterns: (1) transient, (2) prolonged, and (3) delayed opening. This variation in the development of barrier disruption may be related to the secondary barrier failure as well as the primary opening after injury.

[The effects of mild hypothermia on expression of stress protein (HSP72) after experimental brain injury]

Recent studies have demonstrated that mild hypothermia protects brain from ischemic insults. In the present study, we investigated the effects of mild hypothermia on stress responses of the neurons and glia after experimental brain injury. We evaluated the immunocytochemical expression of 72kDa molecular weight heat shock protein (HSP72) as a marker of cellular injury. Adult male Sprague-Dawley rats were subjected to a lateral fluid percussive injury. After injury the animals were divided into two groups (normothermic and hypothermic groups). Body temperature of the normothermic groups was maintained at 37.0-37.5 degrees C throughout the experiment. In the latter groups, the rats were exposed to hypothermia of 30.0-31.5 degrees C by surface cooling for 150 minutes beginning at 15 minutes after injury. Animals in each groups were sacrificed at 24, 48, and 72 hours after injury. Vibratomed brain sections were provided for immunocytochemical staining of HSP72 and hematoxyline-eosin staining. The induction of HSP72 was evaluated under the light microscopic level. Results 1) The rats that produced HSP72 in the hypothermic group were significantly less than those in the normothermic group. 2) HSP72 was expressed in the neurons and glia in the various brain regions including the impact site, parasagittal cortex, deep cortical layer, hippocampus, caudate-putamen and midbrain in both groups. However HSP72 positive cells in each brain region of the hypothermic group were significantly less than those in the corresponding regions of the normothermic group.(ABSTRACT TRUNCATED AT 250 WORDS)

Hepatitis C virus RNA and long-term response to recombinant interferon-alpha 2b in patients with chronic hepatitis C

The effectiveness of recombinant interferon-alpha 2b (rIFN-alpha 2b) in eradicating hepatitis C virus (HCV) RNA from serum has not been completely assessed. We studied 39 patients with compensated chronic hepatitis C diagnosed by liver biopsy and positive HCV RNA measured by polymerase chain reaction (PCR). Group I consisted of 26 patients treated with 3 MU of rIFN-alpha 2b for 6 months; group II, 13 control patients observed for six months; and group III, 12 out of 13 patients from group II who subsequently received 5 MU of rIFN-alpha 2b for 6 months. In group I, 11 out of 23 (47.8%) patients who completed treatment had an immediate response and five (21.7%) had a sustained response to therapy six months after treatment. No response was observed in patients from group II. In group III, 7 out of 12 (58.3%) patients who completed treatment had an immediate response and none had a sustained response. Considering all patients who completed rIFN-alpha 2b treatment, HCV RNA remained positive at the end of therapy in three of five sustained responders (60%), six of 13 patients who relapsed (46.1%), and in all nonresponders (100%). HCV RNA was positive 6 months after therapy in four (80%), 13 (100%), and 17 (100%) patients respectively. All patients with a sustained response had normal aminotransferase levels 18 months after therapy. We conclude that in chronic hepatitis C rIFN-alpha 2b causes a significant immediate response but this is not sustained, only 2.8% of treated patients had a sustained loss of HCV RNA. Normal aminotransferase persist in the long term, despite persistence of HCV RNA.

Molecular cloning of the gene which encodes beta-N-acetylglucosaminidase from a marine bacterium, Alteromonas sp. strain O-7

The gene encoding the periplasmic beta-N-acetylglucosaminidase (GlcNAcase B) from a marine Alteromonas sp. strain, O-7, was cloned and sequenced. The protein sequence of GlcNAcase B revealed a highly significant homology with Vibrio GlcNAcase and alpha- and beta-chains of human beta-hexosaminidase.

[Breakdown of the blood-brain barrier and clearance of extravasated proteins after experimental brain injury]

It is well recognized that extravasation of circulating proteins is contributed to the formation of vasogenic brain edema after traumatic brain injury. However, clearance of the extravasated proteins from brain tissue remains unclear. In the present study we therefore identified the clearance procedure by evaluating extravascular localization of endogenous serum albumin and exogenous protein tracer, horseradish peroxidase (HRP), after experimental brain injury in rats. Adult male Wistar rats were subjected to a lateral fluid percussive injury. In study 1, HRP was given intravenously 10 minutes before sacrifice. Animals were sacrificed at 1, 2, 24, 72 hours and 7 days after injury in order to determine re-establishment of the blood-brain barrier. In study 2 extravascular accumulation of serum albumin and HRP given before impact was examined at 1, 6, 24, 72 hours and 7 days after injury to evaluate the clearance of these extravasated proteins. Localization of each protein was assessed in injured brain sections at the microscopic level. In study 1, breakdown of the blood-brain barrier was noted in various regions of the injured brain at 1 hour. This barrier disruption was restored in almost regions by 2 hours. Impact site, however, remained permeable upto 72 hours. In study 2, the distribution of extravasated proteins was similar between albumin and HRP at 1 hour post-injury. Pronounced extravasation of both proteins occurred in discrete regions through the injured brain. After 6 hours post-injury a differential accumulation was noted between albumin and HRP. The diffuse extracellular accumulation of albumin was most widespread at 24 hours and less intense at 72 hours.(ABSTRACT TRUNCATED AT 250 WORDS)

Comparative study of three doses of interferon-alpha 2a in chronic active hepatitis B. The International Hepatitis Trial Group

To determine the efficacy of interferon-alpha 2a in chronic active hepatitis B, 238 patients were randomly divided, into four groups: three groups received either 2.5 MIU m-2, 5.0 MIU m-2 or 10.0 MIU m-2, three times weekly by intramuscular injection for 12-24 weeks; and a control group received no treatment. Patients were followed for up to 12 months after treatment was discontinued. There was a statistically significant difference in response [clearance of hepatitis B e antigen (HBeAg) and hepatitis B viral DNA (HBV-DNA)] between treated and untreated patients (37 vs 13%) but no statistically significant difference was seen between treatment groups (33%, 34% and 43% for the 2.5, 5.0 and 10.0 MIU m-2 groups, respectively). A transient rise in transaminases (seroconversion hepatitis) was seen in responders, but levels returned to within the normal range after response to treatment. In patients responding to interferon therapy there was a significant reduction in the severity of the hepatitis. Interferon-alpha 2a was generally well tolerated with respect to vital signs and laboratory parameters.

Gene sequence, purification and characterization of N-acetyl-beta-glucosaminidase from a marine bacterium, Alteromonas sp. strain O-7

The gene (cht60) encoding N-acetyl-beta-glucosaminidase (Cht; EC 3.2.1.30) from the marine bacterium Alteromonas sp. strain O-7 was cloned into pUC18 in Escherichia coli JM109. The nucleotide (nt) sequence of cht60 was determined. A 1797-bp open reading frame encoded a polypeptide of 598 amino acids (aa) (M(r) 64,535). The aa sequence of the cloned enzyme (Cht60) deduced from the nt sequence showed no significant sequence homologies with available aa sequences from databases. Cht60 was purified from the periplasmic fraction of E. coli cells carrying pCHT982. The enzyme was most active towards p-nitrophenyl-N-acetyl-beta-D-glucosaminide(PNP-beta-GlcNAc) and diacetylchitobiose. The optimum pH and temperature of the enzyme were pH 7.5 and 37 degrees C, respectively. The N-terminal 11 aa residues of Cht60 were sequenced, and the location of the signal peptide cleavage site was clarified.

Immunocytochemical localization of immunoglobulins in the rat brain: relationship to the blood-brain barrier

The central nervous system has been traditionally regarded as an immunologically privileged area. This feature has been in part attributed to the blood-brain barrier, which provides a restrictive interface to circulating immunoglobulins (IgG). Recent kinetic studies suggest that the barrier to immune proteins is not absolute, but rather may be regulated by a specific transfer mechanism. In this study, we confirm the presence of IgG in the central nervous system by immunocytochemistry and demonstrate a close anatomical relationship between the distribution of this protein and the blood-brain barrier. IgG was immunolocalized in the normal rat brain by using monoclonal and polyclonal antibodies to IgG and its subclasses. On the basis of an initial evaluation, the most appropriate antibodies and dilutions were selected for subsequent analyses. In the first study, IgG and albumin were immunolocalized in adjacent sections. In the second study, horseradish peroxidase (HRP) was given intravenously prior to sacrifice, in order to examine artifacts related to perfusion fixation. The distribution of HRP and IgG was then examined in adjacent sections. In the third study, IgG was immunolocalized in sections of brain after mild traumatic head injury. A monoclonal antibody to IgG2a and a polyclonal antibody to IgG were selected on the basis of specificity and consistent, mutual localization. Distinct, patchy, perivascular staining, infrequently associated with labeled neurons, was noted throughout the brain. Electron microscopy confirmed the perivascular localization; IgG was localized along the basal lamina of microvasculature and within the adjacent parenchyma. Albumin and HRP did not exhibit a similar pattern of perivascular immunostaining. After head injury, prominent immunostaining for IgG was observed in the injured hemisphere. In summary, these data indicate that the normal rat brain contains IgG, which dramatically increases after head injury. The distinct perivascular distribution in the normal brain suggests local microvascular permeability. This permeability is selective for IgG, since albumin does not share a similar perivascular localization. The neuronal staining which is closely associated with perivascular label may reflect one intracellular route for extravasated IgG.

Propranolol compared with propranolol plus isosorbide dinitrate in portal-hypertensive patients: long-term hemodynamic and renal effects

The long-term hemodynamic and renal effects of propranolol were compared with those of propranolol plus isosorbide dinitrate in 44 portal-hypertensive alcoholic cirrhotic patients. Eight control patients, 8 patients receiving propranolol and 14 patients receiving propranolol plus isosorbide dinitrate were hemodynamically evaluated. Renal function was studied in a fourth group of 14 patients receiving propranolol plus isosorbide dinitrate. Portal pressure decreased more (p < 0.05) with combined therapy (-21.6%, from 19.5 +/- 4.8 to 15.4 +/- 4.3 mm Hg) than with propranolol alone (-12.5%, from 19.9 +/- 1.2 to 17.4 +/- 1.8 mm Hg). Serum urea and creatinine levels, plasma sodium concentration, urine volume and urinary sodium excretion showed nonsignificant changes in all groups studied. Combined therapy induced a significant (p < 0.05) decrease in plasma renin activity (from 4.42 +/- 4.7 to 1.59 +/- 1.9 ng/ml/hr) and nonsignificant reductions in plasma aldosterone concentration and creatinine clearance. None of the eight patients with ascites or history of ascites not receiving isosorbide dinitrate showed evidence of impairment in renal sodium metabolism during the study period. In contrast, 8 of the 14 patients (57%) with ascites or history of ascites receiving isosorbide dinitrate showed impairment in renal sodium metabolism (p < 0.01), as reflected by the development or worsening of ascites and the need of higher diuretic requirements. Long-term combined administration of propranolol plus isosorbide dinitrate is superior to propranolol alone in the pharmacological treatment of portal hypertension.(ABSTRACT TRUNCATED AT 250 WORDS)

Immunolocalization of heat shock protein after fluid percussive brain injury and relationship to breakdown of the blood-brain barrier

We have previously developed a model of mild, lateral fluid percussive head injury in the rat and demonstrated that although this injury produced minimal hemorrhage, breakdown of the blood-brain barrier was a prominent feature. The relationship between posttraumatic blood-brain barrier disruption and cellular injury is unclear. In the present study we examined the distribution and time course of expression of the stress protein HSP72 after brain injury and compared these findings with the known pattern of breakdown of the blood-brain barrier after a similar injury. Rats were subjected to a lateral fluid percussive brain injury (4.8-5.2 atm, 20 ms) and killed at 1, 3, and 6 h and 1, 3, and 7 days after injury. HSP72-like immunoreactivity was evaluated in sections of brain at the light-microscopic level. The earliest expression of HSP72 occurred at 3 h postinjury and was restricted to neurons and glia in the cortex surrounding a necrotic area at the impact site. By 6 h, light immunostaining was also noted in the pia-arachnoid adjacent to the impact site and in certain blood vessels that coursed through the area of necrosis. Maximal immunostaining was observed by 24 h postinjury, and was primarily associated with the cortex immediately adjacent to the region of necrosis at the impact site. This region consisted of darkly immunostained neurons, glia, and blood vessels. Immunostaining within the region of necrosis was restricted to blood vessels. HSP72-like immunoreactivity was also noted in a limited number of neurons and glia in other brain regions, including the parasagittal cortex, deep cortical layer VI, and CA3 in the posterior hippocampus.(ABSTRACT TRUNCATED AT 250 WORDS)

Cloning, sequence, and expression of a chitinase gene from a marine bacterium, Altermonas sp. strain O-7

The gene encoding an extracellular chitinase from marine Alteromonas sp. strain O-7 was cloned in Escherichia coli JM109 by using pUC18. The chitinase produced was not secreted into the growth medium but accumulated in the periplasmic space. A chitinase-positive clone of E. coli produced two chitinases with different molecular weights from a single chitinase gene. These proteins showed almost the same enzymatic properties as the native chitinase of Alteromonas sp. strain O-7. The N-terminal sequences of the two enzymes were identical. The nucleotide sequence of the 3,394-bp SphI-HindIII fragment that included the chitinase gene was determined. A single open reading frame was found to encode a protein consisting of 820 amino acids with a molecular weight of 87,341. A putative ribosome-binding site, promoter, and signal sequence were identified. The deduced amino acid sequence of the cloned chitinase showed sequence homology with chitinases A (33.4%) and B (15.3%) from Serratia marcescens. Regardless of origin, the enzymes of the two bacteria isolated from marine and terrestrial environments had high homology, suggesting that these organisms evolved from a common ancestor.

A controlled trial of high dose interferon, alone and after prednisone withdrawal, in the treatment of chronic hepatitis B: long term follow up

This study was designed to evaluate the safety and effectiveness of high dose interferon, with or without prednisone pretreatment, in patients with chronic hepatitis B. Patients were randomised to two treatment groups: group I (n = 26) received six weeks of prednisone followed by a two week, drug free period, and then 10 million units (MU) of interferon alfa-2b three times weekly subcutaneously for 16 weeks; group II (n = 24) were used as controls for 24 weeks and then treated with interferon. Loss of hepatitis B e antigen (HBeAg) and hepatitis B virus (HBV)-DNA, with a return to normal alanine aminotransferase (ALT) activity, was seen in 16 of 26 group I patients (61.5%), in one group II patient (4.2%) during the control phase, and in 13 of 23 group II patients (56.5%) after interferon. Three of 26 (11.5%) in group I and one of 23 (4.3%) in group II eliminated the surface antigen (HBsAg). There were no statistically significant differences in response between groups I and II. Liver biopsies carried out in 20 patients showed that responders had a noticeable reduction in inflammation and disappearance of core antigen in liver tissue, changes not seen in non-responders. On long term follow up (four years), nine out of 28 responders (32.1%) eliminated HBsAg, and four initial non-responders had a late seroconversion.

Long-term follow-up of cerebral blood flow in patients with ruptured cerebral aneurysm

The xenon-133 inhalation technique was used to make three measurements of regional cerebral blood flow (CBF) in 34 patients with ruptured cerebral aneurysm: in the acute period (less than 14 days) after subarachnoid hemorrhage, in the subacute period (15-30 days), and in the chronic period (12-24 months). The hemispheric mean value of initial slope index was used as the mean CBF. The clinical outcomes were classified into good recovery (GR) (24 cases), moderate disability (MD) (5), and severe disability (SD) (5) on the Glasgow Outcome Scale. In all periods, the mean CBF significantly correlated with the outcome. GR patients had the highest mean CBF, MD patients the intermediate mean CBF, and SD patients the lowest mean CBF. GR patients had a near-normal mean CBF by the chronic period, while SD patients showed no significant CBF recovery throughout the course.

Breakdown of the blood-brain barrier after fluid percussion brain injury in the rat: Part 2: Effect of hypoxia on permeability to plasma proteins

Clinical studies have demonstrated that hypoxia after severe brain injury is common and significantly worsens neurologic outcome. We have, therefore, developed a rat model of posttraumatic hypoxic injury in order to identify the pathophysiologic responses after head injury that are worsened by this secondary insult. We examined the effect of hypoxia after brain injury on permeability of the blood-brain barrier to plasma proteins. Animals were divided into two experimental groups: group I (impact alone) and group IH (impact plus hypoxia). Rats were subjected to a lateral fluid percussive brain injury (4.8-5.2 atm). Animals in group IH were exposed to hypoxic conditions (10% O2) for 45 min immediately after injury. In each group, vascular permeability to endogenous immunoglobulins (IgG) and to horseradish peroxidase (HRP) was examined at the light microscopic level. IgG was immunolocalized in brain sections at 1-24 h after injury. In other studies, HRP was given i.v. either before impact or 10 min before killing. Permeability to this protein was assessed at 1-72 h after injury. The distribution of extravasated proteins was similar between the experimental groups at 1 h postinjury. Pronounced abnormal permeability to IgG and HRP (given before impact) occurred in discrete regions throughout both the ipsilateral and contralateral hemispheres. By 6 h after injury, a differential response of the blood-brain barrier was noted between groups I and IH. Widespread leakage of proteins was observed in the injured hemisphere in group IH. This finding was in sharp contrast to group I, in which extravasated proteins remained more localized in the injured hemisphere. The time course for reestablishment of the blood-brain barrier to HRP (given before killing) was determined. The impact site remained permeable to HRP up to at least 72 h postinjury within groups I and IH. In group I, the blood-brain barrier was reestablished in the parasagittal cortex and deep cortical layer by 6 h postinjury. In contrast, the blood-brain barrier in group IH was not restored in similar brain regions until 24 h postinjury. These studies demonstrate that (1) hypoxia after brain injury exacerbates the regional breakdown of the blood-brain barrier to circulating proteins, (2) this influence of hypoxia on permeability is not apparent immediately after injury but rather is expressed at 6 h after injury, and (3) hypoxia after traumatic brain injury delays recovery of the blood-brain barrier. These findings suggest that secondary posttraumatic hypoxia contributes to the vascular pathogenesis of brain injury.