VimA-dependent modulation of the secretome in Porphyromonas gingivalis.

The VimA protein of Porphyromonas gingivalis is a multifunctional protein involved in cell surface biogenesis. To further determine if its acetyl coenzyme A (acetyl-CoA) transfer and putative sorting functions can affect the secretome, its role in peptidoglycan biogenesis and effects on the extracellular proteins of P. gingivalis FLL92, a vimA-defective mutant, were evaluated. There were structural and compositional differences in the peptidoglycan of P. gingivalis FLL92 compared with the wild-type strain. Sixty-eight proteins were present only in the extracellular fraction of FLL92. Fifteen proteins present in the extracellular fraction of the parent strain were missing in the vimA-defective mutant. These proteins had protein sorting characteristics that included a C-terminal motif with a common consensus Gly-Gly-CTERM pattern and a polar tail consisting of aromatic amino acid residues. These observations suggest that the VimA protein is likely involved in peptidoglycan synthesis, and corroborates our previous report, which suggests a role in protein sorting.

VimA-dependent modulation of acetyl coenzyme A levels and lipid A biosynthesis can alter virulence in Porphyromonas gingivalis.

The Porphyromonas gingivalis VimA protein has multifunctional properties that can modulate several of its major virulence factors. To further characterize VimA, P. gingivalis FLL406 carrying an additional vimA gene and a vimA-defective mutant in a different P. gingivalis genetic background were evaluated. The vimA-defective mutant (FLL451) in the P. gingivalis ATCC 33277 genetic background showed a phenotype similar to that of the vimA-defective mutant (FLL92) in the P. gingivalis W83 genetic background. In contrast to the wild type, gingipain activity was increased in P. gingivalis FLL406, a vimA chimeric strain. P. gingivalis FLL451 had a five times higher biofilm-forming capacity than the parent strain. HeLa cells incubated with P. gingivalis FLL92 showed a decrease in invasion, in contrast to P. gingivalis FLL451 and FLL406, which showed increases of 30 and 40%, respectively. VimA mediated coenzyme A (CoA) transfer to isoleucine and reduced branched-chain amino acid metabolism. The lipid A content and associated proteins were altered in the vimA-defective mutants. The VimA chimera interacted with several proteins which were found to have an LXXTG motif, similar to the sorting motif of gram-positive organisms. All the proteins had an N-terminal signal sequence with a putative sorting signal of L(P/T/S)X(T/N/D)G and two unique signatures of EXGXTX and HISXXGXG, in addition to a polar tail. Taken together, these observations further confirm the multifunctional role of VimA in modulating virulence possibly through its involvement in acetyl-CoA transfer and lipid A synthesis and possibly by protein sorting.

The presence of 4-hydroxynonenal/protein complex as an indicator of oxidative stress after experimental spinal cord contusion in a rat model.

OBJECT: The authors tested the hypothesis that breach of the blood-spinal cord barrier (BSCB) will produce evidence of oxidative stress and that a similar staining pattern will be seen between 4-hydroxynonenal (HNE)/protein complexes and extravasated immunoglobulin G (IgG). METHODS: Adult female Fischer 344 rats, each weighing 200 to 225 g, were subjected to a spinal cord contusion at T-10 by means of a weight-drop device. Spinal cord tissue was assessed for oxidative stress by localizing extravasated plasma contents with a monoclonal antibody for rat IgG and protein conjugation with HNE, which is an aldehyde byproduct of lipid peroxidation. The animals were killed at 1 and 6 hours, and 1, 2, and 7 days after surgery. Maximum HNE/protein staining was observed at 2 days postinjury, and HNE/protein and IgG manifested similar staining patterns. Analysis revealed a graduated but asymmetrical rostral-caudal response relative to the T-10 injury site. Both HNE/protein complex and IgG staining revealed that the caudal levels T-11 and T-12 stained significantly more intensely than the rostral levels T-9 and T-8, respectively. A higher percentage of neurons positive for HNE/protein immunostaining was observed in spinal cord levels caudal to the injury site compared with equidistant rostral regions. Protein dot-blot assays also revealed a similar asymmetrical rostral-caudal HNE/protein content. To analyze the timing of the BSCB breach, another group of animals received identical contusions, and horseradish peroxidase (HRP) was injected 10 minutes before or at various times after injury (1, 3, and 6 hours, and 1, 2, and 7 days). Maximum HRP permeability was seen immediately after injury, with a significant decrease occurring by 1 hour and a return to control levels by 2 days posttrauma. CONCLUSIONS: Data from this study indicate possible compromise of neuronal, axonal, glial, and synaptic function after trauma, which may be a factor in motor deficits seen in animals after spinal cord contusion. The colocalization of the IgG stain with the HNE/protein stain is consistent with the hypothesis of a mutual cause-effect relationship between BSCB and oxidative stress in central nervous system trauma.

Evaluation of the 'golden period' for wound repair: 204 cases from a Third World emergency department.

Uncertainty about the existence and duration of a "golden period" for suture repair of simple wounds led us to evaluate prospectively the consequences of delayed primary closure on wound healing. Wounds were eligible for study if they were not grossly infected, and had no associated injuries to nerves, blood vessels, tendons, or bone. Three hundred seventy-two patients underwent suture repair; 204 (54.8%) returned for review seven days later. The mean time from wounding to repair for all patients was 24.2 +/- 18.8 hours. Wounds closed at up to 19 hours after wounding had a significantly higher rate of healing than those closed later: 82 of 89 (92.1%) compared with 89 of 115 (77.4%) (P less than .01). Of 23 wounds sutured 48 or more hours (mean, 65.3) after wounding, 18 (78.3%) were healing at follow-up. In contrast to wounds involving other body areas, the healing of head wounds was virtually independent of time from injury to repair: 42 of 44 (95.5%) wounds involving the head and repaired later than 19 hours after injury were healing, compared with 47 of 71 (66.2%) of all other wounds (P less than .001). On the basis of these data we conclude that there is a 19-hour "golden period" for repair of simple wounds involving body areas other than the head, after which sutured wounds are significantly less likely to heal, and the healing of clean, simple wounds involving the head is unaffected by the interval between injury and repair.

Evaluation of the "golden period" for wound repair: 204 cases from a third world emergency department

Uncertainty about the existence and duration of a "golden period" for suture repair of simple wounds led us to evaluate prospectively the consequences of delayed primary closure on wound healing. Wounds were eligible for study if they were not grossly infected, and had no associated injuries to nerves, blood vessels, tendons, or bone. Three hundred seventy-two patients underwent suture repair; 204 (54.8 percent) returned for review seven days later. The mean time from wounding to repair for all patients was 24.2ñ18.8 hours. Wounds closed at up to 19 hours after wounding had a significantly higher rate of healing than those closed later: 82 of 89 (92.1 percent) compared with 89 of 115 (77.4 percent) (P less than .01). Of 23 wounds sutured 48 or more hours (mean, 65.3) after wounding, 18 (78.3 percent) were healing at follow-up. In contrast to wounds involving other body areas, the healing of head wounds was virtually independent of time from injury repair: 42 of 44 (95.5 percent) wounds involving the head and repaired later than 19 hours after injury were healing, compared with 47 of 71 (66.2 percent) of all other wounds (P less than .001). On the basis of these data we conclude that there is a 19-hour "golden period" for repair of simple wounds involving body areas other than the head, after which sutured wounds are significantly less likely to heal, and the healing of clean, simple wounds involving the head is unaffected by the interval between injury and repair. (AU)

The effect of late primary repair on healing of simple wounds: analysis of 207 cases - abstract

Although orthodox doctrines of wound care dictate that wounds presenting after a "golden period" of six to 24 hours should be managed with delayed closure, the large number of late presenting wound seen in the Casualty Department, Kingston Public Hospital, makes delayed management problematic. We therefore decided to study, prospectively, the consequences of delayed mangement problematic. We therefore decided to study, prospectively, the consequences of delayed primary closure on wound healing. All wounds seen by the authors between June and September, 1986 were considered eligible for inclusion if (1) they were not grossly infected, (2) there were no associated injuries to structures such as nerves, blood vessels and tendons, and (3) the patients were capable of relating the time of wounding and returning for follow-up. Shortages of sterile equipment necessitated closure of up to eight wounds with each suture set and pair of sterile gloves. Four hundred and sixty-eight patients underwent suture repair; two hundred and seven (44.2 percent) returned for review. The results are summarized as follows: HOURS; - 0-6, 7-12, 13-24, 25-48, >48; (MEAN) - (4.4), (9.3), (20.2), (32.3), (63.8) respectively; SUTURED; - 28, 47, 65, 47, 20 respectively; HEALING; 25, 45 51, 35, 15 respectively; percentHEALING - 89.3, 95.7, 78.5, 74.4, 75.0 respectively. ALL: (22.5), 207, 171, 82.6 respectively. When patients were considered according to whether repair was performed within 22 hours or later, the following was found: HOURS -<22, >22; (M) - (10.3), (35.6) respectively; SUTURED - 107, 100 respectively, HEALING - 98, 73 respectively; percent HEALING - 91.6, 73.0 respectively. The difference in healing between these two groups is significant at the p<0.001 level. We conclude that, although wounds sutured within 22 hours after injury have a significantly greater chance of healing than those repaired later, this advatage is relative, not absolute. The success experienced when suturing was performed more than 48 hours after injury indicates that primary repair is a practical, safe way of managing uncomplicated, late presenting wounds (AU)