Postoperative hemiparesis due to conversion disorder after moderate sedation: a case report.

Peri-operative conversion disorder that manifests as postoperative muscle weakness is an uncommon diagnosis made through exclusion of neurological, metabolic or iatrogenic aetiologies. We present a case where a patient with a considerable history of physical and psychological trauma suffered from prolonged right-sided hemiparesis following a breast biopsy under moderate-to-deep sedation. Conversion disorder following moderate-to-deep sedation has yet to be discussed in the literature, as all previous cases have described postoperative conversion disorder in the setting of general or central neuraxial anaesthesia. Our recommendation is for practitioners to keep conversion disorder on the list of differential diagnoses, despite the depth of sedation or type of anaesthetic utilised, and perform the same detailed neurological, metabolic and psychiatric assessment when considering postoperative weakness.

Differential capacity for complement receptor-mediated immune evasion by Porphyromonas gingivalis depending on the type of innate leukocyte.

The complement system plays a central role in immunity and inflammation, although certain pathogens can exploit complement to undermine protective immunity. In this context, the periodontal keystone pathogen Porphyromonas gingivalis was previously shown by our group to evade killing by neutrophils or macrophages through exploitation of complement C5a receptor 1 (C5aR1) and complement receptor 3 (CR3). Here, we examined whether P. gingivalis uses complement receptors to also subvert killing by dendritic cells. In line with earlier independent studies, intracellular viable P. gingivalis bacteria could be recovered from mouse bone-marrow-derived dendritic cells (BMDC) or human monocyte-derived dendritic cells (MDDC) exposed to the pathogen. However, in the presence of C5a, the intracellular survival of P. gingivalis was significantly decreased in a C5aR1-dependent way. Further work using wild-type and receptor-knockout BMDC showed that, in the presence of C3a, the C3a receptor (C3aR) similarly enhanced the intracellular killing of P. gingivalis. In contrast, C5aR2, an alternative receptor for C5a (G protein-coupled receptor 77), was associated with increased intracellular P. gingivalis viable counts, consistent with the notion that C5aR2 functions as a negative regulator of C5aR1 activity. Moreover, P. gingivalis failed to use CR3 as a phagocytic receptor in BMDC, in contrast to our earlier findings in macrophages where CR3-mediated uptake promotes P. gingivalis survival. Collectively, these data show that complement receptors mediate cell-type-specific effects on how innate leukocytes handle P. gingivalis, which appears to exploit complement to preferentially evade those cells (neutrophils and macrophages) that are most often encountered in its predominant niche, the periodontal pocket.

Dendritic cells at the oral mucosal interface.

The mucosal lining of the respiratory and digestive systems contains the largest and most complex immune system in the body, but surprisingly little is known of the immune system that serves the oral mucosa. This review focuses on dendritic cells, particularly powerful arbiters of immunity, in response to antigens of microbial or tumor origin, but also of tolerance to self-antigens and commensal microbes. Although first discovered in 1868, the epidermal dendritic Langerhans cells remained enigmatic for over a century, until they were identified as the most peripheral outpost of the immune system. Investigators' ability to isolate, enrich, and culture dendritic cells has led to an explosion in the field. Presented herein is a review of dendritic cell history, ontogeny, function, and phenotype, and the role of different dendritic cell subsets in the oral mucosa and its diseases. Particular emphasis is placed on the mechanisms of recognition and capture of microbes by dendritic cells. Also emphasized is how dendritic cells may regulate immunity/tolerance in response to oral microbes.

Oral mucosal expression of HIV-1 receptors, co-receptors, and alpha-defensins: tableau of resistance or susceptibility to HIV infection?

The basic premise of whether transmission of HIV-1 through the oral mucosa actually occurs, and through what route, is a topic of intense interest. Our work has focused on HIV-1 receptors/co-receptors and alpha-defensin-1 in situ in human gingiva. Regardless of HIV-1 infection, the role that C-type lectin receptors might play in periodontal pathogenesis is of great interest. We have shown that the gingival lamina propria, when inflamed, becomes increasingly infiltrated with DC-SIGN+MR+ dermal dendritic cells (DDCs), while the inflamed epithelium shows a decrease in Langerin+ Langerhans cells (LCs). Moreover, DDCs and LCs contribute to the mature CD83+ DC pool in situ, and form immune conjugates with CD4+ T-cells in the lamina propria (Jotwani and Cutler, 2003). This raises the intriguing possibility that oral mucosal DCs may be involved in HIV-1 transfer to T-cells in situ. However, this possibility is tendered by the challenges faced by the virus in gaining access to oral mucosal immune cells, including their ability to survive the salivary defenses, cross the mucosal barrier, resist inactivation by alpha-defensins, and overcome the paucity of co-receptor CCR5 in (healthy) oral mucosa (i.e., required for productive infection [Jotwani et al., 2004]). To date, there is little evidence of direct infection by HIV-1 of oral mucosal DCs/T cells and other cells in situ. Abbreviations used in this paper: CP, chronic periodontitis; CCR5, chemokine receptor 5; CXCR4, C-X-C receptor 4; DCs, dendritic cells; DC-SIGN, DC-specific ICAM-3 grabbing non-integrin; DDC, dermal dendritic cells; LCs, Langerhans cells; LP, lamina propria; MR, mannose receptor.

Cytokine stimulation during Salmonella typhimurium sepsis in Itys mice.

Cytokine production was measured in mice during Salmonella typhimurium sepsis and intoxication. In mice given live S. typhimurium (10 cfu/mouse), by intra-peritoneal injection, serum levels of tumour necrosis factor (TNF)-alpha and interleukin-6 increased steadily from day 1 until day 4. Interferon-gamma levels showed a transient peak on day 3. Interleukin-1-alpha levels were very low. There were high bacterial counts in the livers at day 3 and deaths occurred from day 4 onwards. Intraperitoneal injection of lipopolysaccharide or heat-killed bacteria also induced all of the cytokines, but their time of appearance and levels varied greatly. Cytokine induction by heat-killed bacteria was more marked. Endotoxaemia decreased with time during intoxication and increased during sepsis. Bioactive TNF, as measured by a cytotoxicity assay, was found only in mice given heat-killed bacteria.

Multiple dendritic cell (DC) subpopulations in human gingiva and association of mature DCs with CD4+ T-cells in situ.

Gingival epithelium is a site of active trafficking of Langerhans cells (LCs), while the lamina propria in chronic periodontitis (CP) contains CD83+ mature dendritic cells (mDCs) and CD4+ T-cells. The immune cells that contribute to the mDCs, and whether mDCs engage with T-cells in situ, are unclear. Using several immunohistochemical approaches, combined with fluorescence-, light-, and scanning laser confocal-microscopy, we show that, in addition to LCs, the gingiva contains dermal DCs (DDCs) in the lamina propria; moreover, DDCs increase in number during CP. Furthermore, DDCs, LCs, and B-cells co-express CD83 in CP and contribute to the mDC pool. Double-staining for CD83 and CD4 revealed that mDCs associate with clusters of CD4+ T-cells in the lamina propria. Analysis of these data suggests that multiple DC subsets mature in the gingiva and that mature DCs engage in antigen presentation with T-cells in chronic periodontitis.

Increase in HIV receptors/co-receptors/alpha-defensins in inflamed human gingiva.

Transmission of HIV-1 through the oral cavity is considered to be a rare event. To identify factors in resistance/susceptibility to oral HIV-1 infection, we analyzed expression in human gingiva of HIV-1 receptors Langerin, DC-SIGN, MR, and GalCer, HIV-1 co-receptors CCCR5, CXCR4, and anti-microbial protein alpha-defensin-1. Our results show that healthy gingiva is infiltrated with cells expressing all HIV-1 receptors tested; however, there are very few CCR5(+) cells and a complete absence of CXCR4(+) cells in the lamina propria. In chronic periodontitis (CP), DC-SIGN, MR, CXCR4, and CCR5 increase, but this was accompanied by a ten-fold increase in alpha-defensin-1 mRNA. The CCR5(+) cells were revealed to be T-cells, macrophages, and dermal dendritic cells. Moreover, epithelial expression of GalCer and CXCR4 together was not apical and showed no trend with underlying inflammation. Thus, low expression of HIV-1 co-receptors in health and high expression of alpha-defensin during CP may comprise endogenous factors that provide protection from oral HIV-1 infection.

Heightened gingival inflammation and attachment loss in type 2 diabetics with hyperlipidemia.

BACKGROUND: Our previous studies in diabetic (DB) rats suggest that hyperlipidemia may cause a dysregulation of the cellular and local cytokine response to periodontitis (AP). The objective of the present study was to determine if diabetes has a similar dysregulatory effect on the gingival response to AP in humans. METHODS: Peripheral blood, as well as gingival tissue (GT) and gingival crevicular fluid (GCF), was obtained from a total of 35 patients who were categorized into the following groups based on level of diabetic (type 2) control and presence or absence of adult periodontitis (AP): group 1, systemically and periodontally healthy (n = 6); group 2, systemically healthy with adult periodontitis (n = 7); group 3, well-controlled diabetes and periodontally healthy (n = 6); group 4, well-controlled diabetes with adult periodontitis (n = 5); group 5, poorly controlled diabetes and periodontally healthy (n = 5); group 6, poorly controlled diabetes and adult periodontitis (n = 6). All subjects were given a thorough periodontal examination, including probing depths (PD), clinical attachment levels (CAL), gingival index (GI), plaque index (PI), and vertical bitewing radiographs. Blood studies included levels of glycated hemoglobin (HbA1c), triglycerides (TG), cholesterol (CHL), low-density lipoproteins (LDL), and high-density lipoproteins (HDL). The levels of interleukin-1 beta (IL-1beta) in GCF and GT, interleukin-6 (IL-6), and platelet-derived growth factor AB (PDGF-AB) in GT from patients in each experimental group were analyzed by enzyme-linked immunosorbent assay (ELISA). RESULTS: Our results indicate that all clinical indices except PI were significantly elevated in the poorly controlled and well-controlled diabetics, compared to systemically healthy patients, but only in the subjects without preexisiting AP (Tukey's multiple comparisons, P <0.05). Pairwise linear regression analysis revealed significant (P <0.01) positive associations between periodontal inflammation (PD, CAL, PI, GI) and levels of GCF IL-1beta, GT IL- 1beta GT IL-6, but not GT PDGF; moreover, GT IL-6 levels were significantly associated (P<0.05) with GT IL-1beta. As TG levels increased in the non-AP patients (group 1 < group 3 < group 5), there was a trend, not significant, for increased GCF IL-1beta levels and increased gingival inflammation. Interestingly, periodontitis resulted in increased PDGF-AB levels in the gingiva of systemically healthy and well-controlled diabetes patients, but this increase was obtunded in poorly controlled diabetes patients. CONCLUSIONS: This confirms our earlier work in the diabetic rat model. These studies indicate that decreased metabolic control in type 2 diabetics results in increased serum triglycerides and has a negative influence on all clinical measures of periodontal health, particularly in patients without preexisting periodontitis. Levels of the cytokine IL- 1beta showed a trend for increasing as diabetic control diminished. In contrast, levels of the growth factor PDGF, which normally increase in periodontitis, decreased in poorly controlled diabetics with periodontitis. These studies suggest a possible dysregulation of the normal cytokine/growth factor signaling axis in poorly controlled type 2 diabetics that may contribute to periodontal breakdown/diminished repair.

Association between periodontitis and hyperlipidemia: cause or effect?

BACKGROUND: Epidemiological studies suggest a relationship between periodontitis and coronary artery disease, but the mechanism has not been established. Recent studies in animals indicate that low dose endotoxin, as in a gram-negative infection, can induce hyperlipidemia and myeloid cell hyperactivity. The association between periodontitis, systemic exposure to Porphyromonas gingivalis, lipopolysaccharides (LPS), and hyperlipidemia has not been examined in humans. METHODS: Sera were obtained from 26 adult periodontitis patients and 25 healthy control (C) subjects selected from patients and staff. Serum antibodies against Porphyromonas gingivalis and its LPS were analyzed by enzyme-linked immunosorbent assay (ELISA) and Western blotting, respectively. Serum triglycerides (TG) and cholesterol (CHOL) were assayed by a commercial laboratory. The associations between AP and blood levels of TG, CHOL, and anti-P. gingivalis whole cells and LPS were examined by logistic regression analysis. Peripheral blood polymorphonuclear leukocytes (PMNs) from 6 healthy fasted donors were incubated with purified TG (0.1 mg/ml) for 2 hours at 37 degrees C, stimulated with 100 ng/ml P. gingivalis LPS, and the release of IL-1beta measured by ELISA. RESULTS: The presence of periodontitis was significantly associated with age (odds ratio = 3.5, P = 0.04), elevated TG levels (odds ratio = 8.6, P = 0.0009), elevated CHOL levels (odds ratio = 7, P = 0.004), elevated ELISA titer (odds ratio = 35, P = 0.003) and reactivity with P. gingivalis LPS (odds ratio = 41, P = 0.001). PMNs from all 6 healthy patients released modest levels of IL-1beta (10 to 60 pg/ml) when stimulated with 100 ng/ml P. gingivalis LPS. Addition of TG resulted in a significant increase (P <0.05) in IL- 1beta secreted that ranged from 7 to 150% over LPS alone. No IL-1beta was elicited by TG or vehicle alone. CONCLUSIONS: The results of this study indicate the presence of a significant relationship between periodontitis, hyperlipidemia, and serum antibodies against P. gingivalis LPS that warrants further examination in a larger patient population. Furthermore, these studies indicate that elevated triglycerides are able to modulate IL-1beta production by PMNs stimulated with P. gingivalis LPS.

Virulence factors in Bacteroides fragilis group.

Attempts were made to study the virulence factors in some strains of B. fragilis group in the rat model. Subcutaneous wound abscesses could be produced by 10(9) CFU/ml of live cells of all the five species of B. fragilis group tested. For determination of virulence factor cellular components (capsular polysaccharide and lipopolysaccharide) of B. fragilis were separated using gel filtration technique and injected in rats. Abscesses could be produced only by capsular polysaccharide fraction suggesting it to be the virulence factor. Studies with transmission electron microscope showed presence of capsular polysaccharide in B. fragilis and B. thetaiotaomicron, it was doubtful in B. distasonis and absent in B. ovatus and B. vulgatus. This suggested that virulence factors other than capsular polysaccharide may be responsible for pyogenic lesions in the noncapsulated species of B. fragilis group. The abscess could not be produced by 10(9) CFU/ml of heat killed cells of non-capsulated B. ovatus and B. vulgatus indicating that in live bacteria, a heat labile factor was responsible for the development of abscess.

Pathogenicity of Bacteroides fragilis group in rat intra-abdominal abscesses.

Attempts were made to study the pathogenicity of some strains of Bacteroides fragilis group in the rat intra-abdominal abscess model. Multiple intraabdominal abscesses were produced in 50 to 70% of animals when an inoculum containing 10(9) CFU/ml of any of the five species of Bacteroides fragilis group was injected. Rising homologous antibody titers determined by indirect fluorescent antibody test were observed till the 3rd week when tested last, indirectly confirming the multiplication of the organisms as also evident by viable count of bacteria in the abscesses. In some cases in addition to inoculated organisms some intestinal bacteria like Escherichia coli, Proteus mirabilis and Streptococcus spp. were also recovered from the abscess pus. Studies with the electron microscope showed presence of capsular polysaccharide only in Bacteroides fragilis and Bacteroides thetaiotaomicron. It was doubtful in Bacteroides distasonis and absent in Bacteroides ovatus and Bacteroides vulgatus, suggesting that virulence factor beside the capsular polysaccharide may be playing a role. Further studies are required to investigate the virulence factor responsible for the pathogenicity of noncapsulated species.

Comparison of cytokine induction by lipopolysaccharide of Bacteroides fragilis with Salmonella typhimurium in mice.

Comparison of cytokine stimulation by lipopolysaccharide (LPS) of Bacteroides fragilis and Salmonella typhimurium was done to study the early events occurring in vivo. Mice injected intraperitoneally with either LPS demonstrated endogenous production of all the cytokines studied (tumor necrosis factor-alpha, interferon-gamma and interleukin-6) within 6 hr in the bloodstream. However induction of all the cytokines by B. fragilis LPS (50 micrograms/mouse) was much weaker compared with S. typhimurium LPS (50 micrograms/mouse). Even a dose of S. typhimurium LPS 40 times smaller (1.2 micrograms/mouse) induced cytokines more strongly compared with B. fragilis LPS. Thus, a weak biological response to B. fragilis LPS as evidenced by chick embryo lethality, limulus lysate gelation, LD50 for mice and rabbit pyrogenicity could be due to weak induction of bioactive mediators by LPS.

Effect of Escherichia coli lipopolysaccharide on Bacteroides fragilis abscess formation and mortality in mice.

To study the mechanism of synergism between Bacteroides fragilis and Escherichia coli, the effect of sublethal dose of E. coli lipopolysaccharide (LPS) (25 micrograms/mouse) was checked on B. fragilis abscess formation. LPS was administered prior or after inoculum injection. No significant difference in the abscess size was observed at necropsy on day 6. However, all the groups receiving LPS showed higher incidence of recovery of additional intestinal bacteria (23.5-45.5%) from the abscess pus. When LPS was given 4 hr prior to inoculum administration, 83-100% mortality was observed. Detailed investigation showed autoclaved cecal contents alone could also cause similar mortality. Studies with stimulation of endogenous cytokines by E. coli LPS demonstrated induction of all of them within 3 hr in the blood stream with TNF-alpha demonstrating peak at 1 hr, IL-1 alpha and IL-6 at 4 hr and IFN-gamma between 6-9 hr with moderately high levels at 4 hr. This E. coli LPS-triggered cytokine cascade possibly gets further stimulated by injection of autoclaved cecal contents containing high concentration of endotoxins (1.6 x 10(5) EU/ml) contributed by dead bacteria and lead to the mortality of animals.

Detection of Bacteroides fragilis in clinical specimens by polymerase chain reaction amplification of the neuraminidase gene.

The polymerase chain reaction (PCR) was used in an attempt to detect Bacteroides fragilis by amplifying a segment of the gene encoding B. fragilis neuraminidase. Forty-five reference strains representing 45 species and 113 clinical isolates were tested. Only B. fragilis was PCR positive, except for Bacteroides merdae ATCC 43184, which gave a band by ethidium bromide staining that showed no signal by Southern hybridization. Using a protocol that employed DNA extraction by Sepa Gene kit and a highly sensitive digoxigenin-chemiluminescence detection system, detection of B. fragilis by PCR was in complete agreement with culture results for 44 clinical specimens from which a wide range of aerobic and anaerobic organisms and fungi were recovered.

Evidence and a novel hypothesis for the role of dendritic cells and Porphyromonas gingivalis in adult periodontitis.

We have proposed a novel overall hypothesis and approach to understanding the pathophysiology of adult periodontitis, one of the most common diseases that afflicts the US population. While mortality of the dentition is the most familiar outcome of adult periodontitis, its links with other more severe diseases, including coronary artery disease, respiratory diseases and pre-term labor, cannot be ignored. We have called attention to the many intriguing parallels between adult periodontitis and contact hypersensitivity (CHS). CHS is among the most common of dermatoses that afflicts mankind and one of the most intensively studied of in vivo immune responses. Both adult periodontitis and CHS target the host integument (gingiva or skin) and appear to involve the activation and sensitization of similar subsets of antigen capture and presenting cells, the dendritic cells (DCs), as well as similar T cell subsets. DCs have been termed "nature's adjuvant", being more efficient at antigen-presentation than macrophages or B cells and the only antigen-presenting cells that can stimulate naïve T cells to proliferate. This immunostimulatory capacity can also have detrimental effects for the host, as typified by graft-vs.-host disease and CHS responses. Both AP and CHS involve a predominantly destructive T cell response mediated by both regulatory and effector T cells. In the present paper, we show intriguing evidence that Porphyromonas gingivalis is a unique pathogen in this regard, able to infect, sensitize and activate DCs in vitro and, probably, in situ. Many questions about the role of P. gingivalis-sensitized DCs in adult periodontitis, and of the parallels between adult periodontitis and CHS, however, remain to be answered.

Mature dendritic cells infiltrate the T cell-rich region of oral mucosa in chronic periodontitis: in situ, in vivo, and in vitro studies.

Previous studies have analyzed the lymphoid and myeloid foci within the gingival mucosa in health and chronic periodontitis (CP); however, the principal APCs responsible for the formation and organizational structure of these foci in CP have not been defined. We show that in human CP tissues, CD1a(+) immature Langerhans cells predominantly infiltrate the gingival epithelium, whereas CD83(+) mature dendritic cells (DCs) specifically infiltrate the CD4(+) lymphoid-rich lamina propria. In vivo evidence shows that exacerbation of CP results in increased levels of proinflammatory cytokines that mediate DC activation/maturation, but also of counterregulatory cytokines that may prevent a Th-polarized response. Consistently, in vitro-generated monocyte-derived DCs pulsed with Porphyromonas gingivalis strain 381 or its LPS undergo maturation, up-regulate accessory molecules, and release proinflammatory (IL-1beta, PGE(2)) and Th (IL-10, IL-12) cytokines. Interestingly, the IL-10:IL-12 ratio elicited from P. gingivalis-pulsed DCs was 3-fold higher than that from Escherichia coli-pulsed DCs. This may account for the significantly (p < 0.05) lower proliferation of autologous CD4(+) T cells and reduced release of IFN-gamma elicited by P. gingivalis-pulsed DCs. Taken together, these findings suggest a previously unreported mechanism for the pathophysiology of CP, involving the activation and in situ maturation of DCs by the oral pathogen P. gingivalis, leading to release of counterregulatory cytokines and the formation of T cell-DC foci.

In vitro susceptibility of clinical isolates of Bacteroides fragilis and Bacteroides thetaiotaomicron in Japan.

A nationwide survey of the susceptibility of 433 isolates of Bacteroides fragilis and 149 isolates of Bacteroides thetaiotaomicron was conducted from December 1986 through November 1989 in Japan. These strains were collected from 16 university hospitals and one metropolitan hospital. Metronidazole was the most active drug against both species, with no resistant isolates found. The activity of imipenem and sulbactam-cefoperazone was good, with very low resistance rates determined in Bacteroides fragilis (1.4% and 1.6%, respectively) and in Bacteroides thetaiotaomicron (3.4% for both drugs), and was comparable to that of metronidazole. Cefoxitin, cefmetazole, cefotetan, cefbuperazone, latamoxef and ceftizoxime were found to be more active against Bacteroides fragilis, for which resistance rates were 3.2 to 9.5%, than against Bacteroides thetaiotaomicron, for which resistance rates were 18.1 to 21.8%. Rates of piperacillin resistance in the two species were 12.9% and 26.8%, respectively. Clindamycin was very active at a low concentration (MIC50 of 0.39 to 1.56 mg/l), but 24% and 27.5% of Bacteroides fragilis and Bacteroides thetaiotaomicron isolates, respectively, were resistant to this agent.