Genomewide DNA methylation analysis in combat veterans reveals a novel locus for PTSD

OBJECTIVE

Epigenetic modifications such as DNA methylation may play a key role in the aetiology and serve as biomarkers for post-traumatic stress disorder (PTSD). We performed a genomewide analysis to identify genes whose DNA methylation levels are associated with PTSD.

METHOD

A total of 211 individuals comprising Australian male Vietnam War veterans (n = 96) and males from a general population belonging to the Grady Trauma Project (n = 115) were included. Genomewide DNA methylation was performed from peripheral blood using the Illumina arrays. Data analysis was performed using generalized linear regression models.

RESULTS

Differential DNA methylation of 17 previously reported PTSD candidate genes was associated with PTSD symptom severity. Genomewide analyses revealed CpG sites spanning BRSK1, LCN8, NFG and DOCK2 genes were associated with PTSD symptom severity. We replicated the findings of DOCK2 in an independent cohort. Pathway analysis revealed that among the associated genes, genes within actin cytoskeleton and focal adhesion molecular pathways were enriched.

CONCLUSION

These data highlight the role of DNA methylation as biomarkers of PTSD. The results support the role of previous candidates and uncover novel genes associated with PTSD, such as DOCK2. This study contributes to our understanding of the biological underpinnings of PTSD.

Granulosa cell tumour of the ovary with bilateral mature cystic teratomas. A case report

Granulosa cell tumour with synchronous mature cystic teratoma is extremely rare and only eight cases are documented in the literature. Granulosa cell tumours are low-grade malignancies and need a close follow-up for recurrences which may be late. We report a case of granulosa cell tumour and mature cystic teratoma occurring synchronously in the same ovary in a post-menopausal woman.

Stabilographic analysis of unconstrained standing

Natural standing is characterized by postural changes and several hypotheses have been proposed to explain these changes. In this paper, four hypotheses were investigated by quantifying the number of postural changes in the centre of pressure data from unconstrained standing in different experimental conditions, studying the effects of mechanical loading, visual conditions, and type of support surface and sole of the shoes. The subjects stood for 30 min with no specific instructions other than not to step off a force plate. There were no significant effects on the number of centre of pressure patterns associated with the postural changes due to load, vision, surface and shoes during standing; on average, approximately two centre of pressure patterns per minute were observed in all conditions. The analysis of the centre of pressure data by the commonly used statistical parameters (standard deviation, velocity, and mean frequency of the centre of pressure displacement and area of the stabilogram) also did not reveal any effect of the different conditions.

Interleukin-2 and concanavalin A upregulate a cat2 isoform encoding a high affinity L-arginine transporter in feline lymphocytes

The immunological responses of activated lymphocytes are associated with increased nitric oxide (NO) biosynthesis. Studies in the literature have primarily approached control of NO by focusing on the regulation of the nitric oxide synthase (NOS) isoforms. However, the present study approaches the control of NO synthesis by addressing the regulation of L-arginine availability to lymphocytes via regulation of membrane transport. The guanidino nitrogen of L-arginine is the sole biosynthetic precursor of NO. We investigated cytokine and mitogen regulation of membrane L-arginine transporters for the first time in feline cells. Feline peripheral blood mononuclear cells were treated with interleukin-2 and concanavalin A, then alternatively spliced isoforms of L-arginine transporters known in other species were probed by RT-PCR, using various oligonucleotide primers that hybridized to several regions in common with the isoforms. Both high affinity and low affinity isoforms are encoded by mRNAs arising from mutually exclusive alternative splicing of the primary transcript. A region of 123 bp was obtained that encoded an extracellular polypeptide loop of 41 amino acids. The sequence of this region represented the high affinity L-arginine substrate binding site of a CAT2 transporter polypeptide isoform, but not the CAT2a isoform low affinity binding site. Neither of the inducible isoforms were constitutively expressed in unstimulated feline cells. This is the first report demonstrating that domestic cats possess the cat2 gene encoding an inducible L-arginine transporter, and, furthermore, that the high affinity isoform transcript is activated by interleukin-2 and concanavalin A in feline lymphocytes.

The stimulation of bone formation in vitro by therapeutic ultrasound

A controlled study was performed to evaluate the effects of different ultrasound (US) intensities on 5-day-old mouse calvaria bone in tissue culture. A special technique to apply the US was developed, and the following parameters were measured: collagen and noncollagenous protein (NCP) synthesis (bone formation), and temperature change. It was found that ultrasound at 0.1 W/cm2 (SATA), pulsed 1:4, 3 MHz, 5 min, significantly stimulates bone formation (i.e., the synthesis of collagen and NCP) (p < 0.001 and p < 0.01). However, pulsed ultrasound at higher doses (1.0-2.0 W/cm2 (SATA), pulsed 1:4, 3 MHz, 5 min) significantly inhibited the synthesis of both collagen and NCP (p < 0.05). The temperature measurements showed a maximum rise of 1.8 degrees C [at 2.0 W/cm2 (SATA)] and no detected rise at 0.1 W/cm2 (SATA), suggesting that the effects in this study were primarily nonthermal. These results may reflect the healing effect of US on fractures and osteoradionecrosis and reinforces the use of low intensity US regimens [0.1 W/cm2 (SATA)] in clinical practice.

Sensitization of oral bacteria to killing by low-power laser radiation

Twenty-seven compounds were screened for their ability to sensitize Streptococcus sanguis to killing by light from a 7.3-mW Helium/Neon (HeNe) laser. Bacteria were mixed with various concentrations of the test compounds, spread over the surfaces of agar plates, and then exposed to light from the HeNe laser for various time periods. The plates were then incubated and examined for zones of inhibition. Those compounds found to be effective photosensitizers were then tested against Porphyromonas gingivalis, Actinobacillus actinomycetemcomitans, and Fusobacterium nucleatum. Toluidine blue O, azure B chloride, and methylene blue at concentrations of 0.005% (wt/vol) were effective photosensitizers of all four species, enabling killing of bacteria following exposure to laser light for only 30 s.

A preliminary evaluation of the use of a redox agent in the treatment of chronic periodontitis

A small-scale clinical trial was carried out to evaluate the effect of a redox agent, methylene blue, on microbiological and clinical indices of chronic periodontitis. Methylene blue was applied subgingivally on a daily basis for 7 d to 25 test sites in 7 patients and the sites evaluated clinically and microbiologically for up to 14 d: 25 control sites in the same patients received sterile water. The test sites showed statistically significant differences from the control sites in terms of changes in a number of clinical and microbiological indices. In the test sites the proportions of anaerobes, Gram-negative anaerobes, spirochetes and motile bacteria decreased, as did the crevicular fluid flow, while the proportions of facultative anaerobes and cocci increased. These changes are indicative of a shift towards periodontal health. No significant differences were observed between the test and control sites in terms of bleeding on probing or pocket depth. The encouraging results of this preliminary study suggest that the use of redox agents in the treatment of chronic periodontitis warrants further investigation.

Stimulation of bone collagen and non-collagenous protein synthesis by products of 5- and 12-lipoxygenase: determination by use of a simple quantitative assay

The influence of 5- and 12-lipoxygenase products on the rate of collagen and non-collagenous protein (NCP) synthesis by murine calvarial explants has been investigated using a new assay based on the resistance of native collagen to degradation by pepsin. The reproducibility and simplicity of this assay allows the quantitative estimation of the rate of bone formation in large numbers of cultures. Hydroxyeicosatetraenoic acids (HETEs) stimulated both the rate of collagen and NCP synthesis with maximal stimulation occurring at 10-100 pM. All leukotrienes stimulated collagen synthesis. LTB4, C4 and D4 showed similar dose-responses with maximal activity occurring at 100 pM. LTE4 was less potent only showing activity at 1-10 nM. Only LTD4 demonstrated the capacity to stimulate NCP synthesis with significant stimulation being seen at 10 nM. The extreme sensitivity of bone collagen and NCP synthesis to lipoxygenase products suggests that these mediators may play a physiological role in bone remodelling.

A single-blind comparison of intravenous ondansetron, a selective serotonin antagonist, with intravenous metoclopramide in the prevention of nausea and vomiting associated with high-dose cisplatin chemotherapy

Ondansetron (GR 38032F), a selective antagonist of serotonin subtype 3 receptors, is effective in the prevention of emesis associated with cisplatin as well as other chemotherapeutic agents. In this randomized, single-blind, multicenter, parallel group study, we compared the efficacy and safety of intravenous (IV) ondansetron with IV metoclopramide in the prevention of nausea and vomiting associated with high-dose (greater than or equal to 100 mg/m2) cisplatin chemotherapy. Three hundred seven patients receiving their first dose of cisplatin, either alone or in combination with other antineoplastic agents, were randomized to receive ondansetron 0.15 mg/kg IV every 4 hours for three doses or metoclopramide 2 mg/kg IV every 2 hours for three doses, then every 3 hours for three additional doses. The study prohibited the concurrent administration of other antiemetics or dexamethasone. Patients receiving ondansetron had a higher rate of complete protection from emesis (40% v 30%, P = .07), a higher complete plus major response rate (65% v 51%, P = .016), a lower rate of failure (21% v 36%, P = .007), and a lower median number of emetic episodes (one v two, P = .005) than did those receiving metoclopramide. The median time to the first emetic episode was longer on ondansetron (20.5 v 4.3 hours, P less than .001). Adverse events occurred in 48% of patients receiving ondansetron and 69% of those receiving metoclopramide (P less than .001). Akathisia and acute dystonic reactions occurred only on metoclopramide; headache (controlled with acetaminophen) was significantly more frequent with ondansetron. Ondansetron is more effective, produces fewer adverse events, and is easier to administer than metoclopramide for the prevention of emesis associated with high-dose cisplatin chemotherapy.

Characterization of a new cell line (ESKOL) resembling hairy-cell leukemia: a model for oncogene regulation and late B-cell differentiation

A B-lymphoblastoid cell line ESKOL, composed of differentiated cells resembling hairy-cell leukemia (HCL) has been established from the peripheral blood (PB) of a HCL patient. Morphologically, ESKOL cells share several features with HCL B cells. Flow cytometric analysis revealed that ESKOL cells express HC2, CD21, PCA-1, CD24, FMC7, and CD25. Analysis by Northern-blot hybridization indicated that cultured cells expressed the oncogenes c-myc, H-ras and c-fos. RNA from 3T3 cells transfected with ESKOL DNA hybridized with H-ras and c-fos DNA probes. The ESKOL cells cultured in the presence of increasing concentrations, of alpha interferon demonstrated a decrease in the rate of cellular growth and an increase in the expression of CD21, CD25, FMC7 and PCA-1. Scanning electron microscopy revealed that cells incubated in the presence of alpha interferon underwent membranous changes with a loss of villosity. These observations suggest that IFN tends to drive HC out of their developmental arrest towards maturation.

Measurement of radiation-induced DNA double-strand breaks by pulsed-field gel electrophoresis

We have examined the use of pulsed-field gel electrophoresis (PFGE) to measure DNA double-strand breaks induced in CHO cells by ionizing radiation. The PFGE assay provides a simple method for the measurement of DNA double-strand breaks for doses as low as 3-4 Gy ionizing radiation, and appears applicable for the measurement of damage produced by any agent producing double-strand breaks. The conditions of transverse alternating field electrophoresis determined both the sensitivity of the assay and the ability to resolve DNA fragments with different sizes. For example, with 0.8% agarose and a 1-min pulse time at 250 V for 18 h of electrophoresis, 0.39% of the DNA per gray migrated into the gel, and only molecules less than 1500 kb could be resolved. With 0.56% agarose and a 60-min pulse time at 40 V for 6 days of electrophoresis, 0.55-0.90% of the DNA per gray migrated into the gel, and molecules between 1500 and 7000 kb could be resolved.

Prevention of bacterial adhesion to denture acrylic

A range of non-toxic polysaccharides were screened for their ability to prevent bacterial adhesion to denture acrylic in vitro. Sodium alginate, karaya gum and carrageenan were found to be the most effective, reducing adhesion of Streptococcus salivarius by 98.7, 97.9 and 99.2 per cent respectively. These three polysaccharides were then tested for their ability to reduce the number of bacteria adhering to dentures in vivo. Sodium alginate was the most effective, reducing the attachment of bacteria to the palate-contacting surface of the denture after 5 h of normal wear by 84 per cent compared with uncoated controls. The results of this investigation suggest that the accumulation of denture plaque may be prevented by frequent application of a renewable, sacrificial coating of a non-toxic polysaccharide.

Selection criteria for local excision with or without adjuvant radiation therapy for rectal cancer

As an alternative to radical surgery, local excision with or without adjuvant pelvic radiation therapy has been used in selected patients with rectal cancer. To determine which clinical and pathologic features can predict the presence of positive lymph nodes (LN+), a retrospective review of 168 patients who underwent potentially curative surgery for rectosigmoid and rectal cancer was performed. By univariate analysis, tumor penetration, grade, and histology were significant predictive features. This was confirmed by logistic regression analysis. The incidence of LN+ increased with increasing tumor penetration (T1, 0%; T2, 28%; T3, 36%; T4, 53%; P = 0.04), grade of adenocarcinoma (well-differentiated, 0%; moderately differentiated, 30%; poorly differentiated, 50%; P = 0.07, [borderline significance]), and the presence of any colloid histology (pure adenocarcinoma, 30%; total colloid, 52%; P = 0.04). Using 2 X 2 contingency tables, the presence of blood vessel invasion (BVI), lymphatic vessel invasion (LVI), vascular invasion (VI), total colloid histology, and high grade further increased the incidence of LN+ with increasing tumor penetration. Regardless of tumor size, grade, histology, BVI, LVI, or VI, none of the nine patients with Stage T1 tumors or the seven with well-differentiated adenocarcinomas had LN+. For this group, local excision alone is recommended. The incidence of LN+ was greater than or equal to 19% in all other categories. For this group of patients, if there is no evidence of gross tumor in the pelvis, then a local excision plus adjuvant pelvic radiation may be an alternative to radical surgery.

Tooth root resorption induced in rats by diphenylhydantoin and parathyroidectomy

Changes in bone, cartilage and the dentition in animals and man following the administration of anticonvulsant drugs resemble those seen in hypoparathyroidism and pseudohypoparathyroidism. Groups of 21-day-old rats were treated with diphenylhydantoin, parathyroidectomized, or made hypocalcaemic with a calcium-deficient diet. Histological examination revealed extensive resorption of cementum and dentine in the molars of the drug-treated and parathyroidectomized rats, but not in the hypocalcaemic or control groups. Localization of injected tetracycline by fluorescence showed that the resorption affected the distal side of the tooth roots and had occurred after root formation. No changes in cementum formation on the mesial side of the roots had occurred in any of the experimental groups. These results suggest that diphenylhydantoin induces a condition similar to pseudohypoparathyroidism in which the resistance of tooth roots to resorption is reduced.

Interleukin 1-like activity in cystic lesions of the jaw

Odontogenic cyst capsules were cultured in vitro and the culture media analysed for bone-resorption and interleukin 1-like activity. Five cysts synthesised a non-dialysable bone resorbing factor with significant interleukin 1-like activity. One specimen thought to be a cyst with little interleukin 1 activity proved to be antral lining. The results indicate that interleukin 1 may play an important role in cyst expansion by its direct effects on fibroblast proliferation and bone resorption and by stimulating prostaglandin synthesis in stromal fibroblasts of the cyst capsule.

Macrophage responsiveness to light therapy

Macrophages are a source of many important mediators of wound repair. It was the purpose of this study to see if light could stimulate the release of these mediators. In this study an established macrophage-like cell line (U-937) was used. The cells were exposed in culture to the following wavelengths of light: 660 nm, 820 nm, 870 nm, and 880 nm. The 820-nm source was coherent and polarised, and the others were non-coherent. Twelve hours after exposure the macrophage supernatant was removed and placed on 3T3 fibroblast cultures. Fibroblast proliferation was assessed over a 5-day period. The results showed that 660-nm, 820-nm, and 870-nm wavelengths encouraged the macrophages to release factors that stimulated fibroblast proliferation above the control levels, whereas the 880-nm wavelength either inhibited the release of these factors or encouraged the release of some inhibitory factors of fibroblast proliferation. These results suggest that light at certain wavelengths may be a useful therapeutic agent by providing a means of either stimulating or inhibiting fibroblast proliferation where necessary. At certain wavelengths coherence is not essential.

Murine osteoblasts release bone-resorbing factors of high and low molecular weights: stimulation by mechanical deformation

Murine calvarial osteoblasts in monolayer culture were found to constitutively produce bone-resorbing factors; mechanical deformation significantly increased the synthesis and/or release of these factors. In short-term cultures (2 h) the resorptive activity was largely dialysable, indicating a relative molecular mass (Mr) less than 2000. Intermittent mechanical deformation stimulated the synthesis of these low Mr factors irrespective of serum conditions. Continuous deformation, however, was without effect. When the culture period was extended to 24 h, bone resorptive activity was stimulated by both intermittent and continuous deformation in the presence of 10% serum. This activity was dialysable. Over this same period in cultures with 2% serum, intermittent deformation also produced a non-dialysable bone-resorbing factor. We also cultured osteoblasts for 72 h in serum-free conditions and deformed the cells intermittently. Fractionation of the medium by high pressure liquid chromatography (HPLC) resolved three peaks of bone resorptive activity: peak I (Mr 50-60,000); peak II (Mr 5-20,000); and peak III (Mr less than 1000). Only peaks II and III were stimulated by mechanical deformation. These bone-resorbing factors remain as yet poorly characterized, but none of the activity in the HPLC fractions was attributable to interleukin-1 or prostaglandin E2.

Squamous carcinoma of the gums

We reviewed a 20-year experience with squamous carcinoma of the gums in 347 patients who received definitive therapy. More than three-quarters of the lesions involved the lower gum and all but 37 patients were previously untreated. The proportion of patients with localized tumors (N0) remained the same (64 percent). Surgery continued to be the treatment of choice in 97 percent of patients, but proportionately more patients had a more conservative procedure which preserved lower jaw continuity. The 5-year determinate survival rate was little changed (54 percent). Advanced clinical stage (stages III and IV), prior dental extraction, bone invasion, and involvement of surgical margins were predictive of a lower survival rate on univariate analysis. Clinical stage was the only significant predictor of survival on multivariate analysis. The impact of adjunctive radiotherapy could not be assessed.

Stimulation of bone resorption by lipoxygenase metabolites of arachidonic acid

We have studied the effect of leukotrienes, (LT): B4, C4, D4 and E4 and the hydroxyeicosatetraenoic acids (HETEs) 5-HETE and 12-HETE on bone resorption in vitro. Resorption was measured by colorimetric assay of calcium released from neonatal mouse calvaria maintained in organ culture for 72h. All the LTs and HETEs stimulated bone resorption, with optimum responses at picomolar or nanomolar concentrations. The responses were biphasic, with a decreasing effect at higher concentrations. In contrast, prostaglandin E2 (PGE2) stimulated resorption only at 10nM and above. Indomethacin partially inhibited resorption by LTB4, LTC4 and LTD4, but did not affect resorption stimulated by LTE4, 5-HETE and 12-HETE. These results indicate that lipoxygenase products of arachidonic acid are highly potent bone resorbing factors and may play an important role in the localised bone loss associated with inflammatory lesions.

Macromolecular osteolytic factor synthesised by squamous carcinoma cell lines from the head and neck in vitro is interleukin 1

Three human cell lines derived from oro-pharyngeal squamous cell carcinomas of the head were investigated for bone-resorbing activity in vitro. Culture media from all three spontaneously produced a non-dialysable osteolytic factor with activity in three in vitro assays for interleukin 1 (IL1), viz. the lymphocyte activating factor (LAF) assay, stimulation of collagenase synthesis by articular chondrocytes, and stimulation of prostaglandin E2 synthesis by fibroblasts. Addition of anti-human IL1 antibody to the culture media abolished all the bone-resorbing activity. Fractionation of the cell culture media by high performance liquid chromatography (HPLC) showed a single peak of activity in the chondrocyte assay with an apparent mol.wt of 15-17,000. This co-eluted with activity in a preparation of IL1 from rat peritoneal macrophage cultures. These results indicate that IL1 is responsible for the prostaglandin-independent bone resorbing activity synthesised by these cells in vitro, and may contribute to the bone destruction associated with the tumour.

Prostaglandin synthesis in the pathogenesis of fronto-ethmoidal mucoceles

The fronto-ethmoidal mucocele is a rare condition capable of expansion and erosion of bone. Its etiology is attributed to obstruction of the fronto-nasal duct and inflammation. To elucidate the role of inflammation, mucocele fragments and fibroblasts cultured from them were examined in vitro to assess prostaglandin E2 synthesis. The cultured fibroblasts when stimulated with mononuclear cell culture supernatant produced significant levels of prostaglandin E2 and collagenase, compared with normal frontal sinus mucosa fibroblasts removed at craniotomy. These significantly elevated mucocele levels of prostaglandin E2 (p = less than 0.001) suggest that lining fibroblasts are a major source of bone-resorbing factors, acting under the stimulus of lymphocytes and monocytes and which operate at the mucocele-bone interface, facilitating expansion. This situation closely parallels that already established in odontogenic cysts.

Inhibition of cartilage growth by the anticonvulsant drugs diphenylhydantoin and sodium valproate

Anticonvulsant-treated epileptic children have reduced growth and show skeletal deformities similar to those seen in hypoparathyroidism. In view of the crucial role of chondrocytes in endochondral bone growth we investigated the effects of anticonvulsant drugs on cartilage growth in rats. Rats were injected i.p. with diphenylhydantoin (PHT) or sodium valproate (dipropyl acetate; DPA), or were thyroparathyroidectomized (TPX) to render them deficient in parathyroid hormone (PTH). Cartilage growth, measured as the increase in thickness and cross-sectional area of the femoral epiphysis and the mandibular condyle cartilage, was significantly reduced in the PHT and TPX groups compared with control animals receiving the drug vehicle alone or a 'sham' TPX operation. The cellularity of the cartilage was reduced in all three treatment groups, but DPA had less effect than PHT or TPX. The similarity in effect between TPX and anticonvulsant treatment suggest the drugs may also interfere with the regulation of chondrocyte activity proliferation and matrix synthesis are reduced by anticonvulsant therapy, and that this contributes to the pathogenesis of abnormal skeletal growth in anticonvulsant-treated children.

The use of human gingival fibroblasts in culture for studying the effects of phenytoin on testosterone metabolism

In initial experiments, monolayer cultures of human gingival fibroblasts from healthy male and female subjects were incubated for various time intervals with [4-14C]-testosterone. This was rapidly taken up by the cells to reach 1.8 fmol/50,000 cells by 2 h. At 6, 12 and 24 h, the values were considerably lower (0.1-0.2 fmol/50,000 cells). In order to maintain a sufficient intracellular concentration of testosterone, unlabelled testosterone was incubated in the presence of [14C]-testosterone. This gave optimum yields of metabolites, which were separated by thin-layer chromatography and provisionally identified by comparison of their mobilities with those of authentic steroids. Final characterization of 5 alpha-dihydrotestosterone was achieved by combined capillary gas chromatography-mass spectrometry. The metabolites of testosterone were 5 alpha-dihydrotestosterone (5 alpha-DHT), 4-androstenedione, 5 alpha-androstanedione and 5 alpha-androstanediols, but the quantities formed varied with different cell lines. A similar pattern of metabolites was noted for minced human gingival tissue. Low concentrations of phenytoin generally increased the production of 5 alpha-DHT and 4-androstendione but there were marked variations between individual cell lines with regard to the magnitude of stimulation. Higher concentrations of phenytoin generally caused inhibition of steroid formation but the concentration required for this again varied with different cell lines. Thus human gingival fibroblasts in culture provide a suitable model for the study of testosterone metabolism and of the effects of drugs such as phenytoin. Variation in these effects may be reflected in individual susceptibility to phenytoin-induced gingival overgrowth.

Heterogeneity of bone resorbing factors produced by unstimulated murine osteoblasts in vitro and in response to stimulation by parathyroid hormone and mononuclear cell factors

The bone resorbing activity of factors released from monolayer cultures of osteoblasts (OB) was examined by measurement of calcium released by neonatal mouse calvaria in vitro. Unstimulated conditioned media (CM) were found to contain significant bone resorbing activity, which was partially inhibited by indomethacin, dexamethasone and nordihydroguaiaretic acid. Ultrafiltration of CM (molecular weight cut-off of 5000) revealed bone resorbing activity in the filtrate and retentate. Fractionation of the CM by high-performance liquid chromatography revealed four major peaks of bone resorbing activity. Stimulation of the OB by mononuclear cell factor and parathyroid hormone significantly increased the synthesis and/or release of these factors with a relatively greater increase of lipid-soluble, low molecular-weight activity. These results suggested an important role for relatively small non-popular mediators in hormonally stimulated bone resorption.

Reduction of post-operative swelling by a placebo effect

A placebo effect on post-operative swelling was investigated as a possible model for studying psychological influences on recovery from surgery. 79 patients undergoing removal of impacted third-molars received one of five different procedures shortly after emerging from general anaesthetic. These included dentist-administered or placebo ultrasound (the latter given in two different ways to control for massage effects), untreated controls and a group instructed to apply facial massage to themselves. Pre- and post-operative measurements included trait and state-anxiety, coping style, emotional state, pain, plasma cortisol and facial swelling. Cortisol levels correlated with anxiety and avoidant coping. Post-operative anxiety was negatively correlated with pre-operative arousal. Neither coping nor emotional state was affected by the treatments, but swelling was reduced by a placebo effect of ultrasound. Cortisol levels also responded, apparently to an effect of massage. The coping and emotional factors which we measured here cannot, therefore, explain the effects of this psychological procedure on post-operative recovery.

The role of lipopolysaccharides in endotoxin-induced thymocyte proliferation and chondrocyte collagenase synthesis

Crude endotoxin preparations from Haemophilus actinomycetemcomitans and Bacteroides gingivalis showed activity in the two principal bio-assays for interleukin 1--the lymphocyte activating factor assay and stimulation of chondrocyte collagenase synthesis. Lipopolysaccharides purified from the crude endotoxins had reduced activity in the chondrocyte collagenase assay. The activity of the endotoxins may be due to synergic interaction between their lipopolysaccharides and other, as yet unidentified, bacterial components.

Psychological factors influencing post-operative pain and analgesic consumption

The personality factors, post-operative pain experience and analgesic requirements after minor oral surgery under general anaesthesia of 103 patients are presented. Psychiatric morbidity, neuroticism and anxiety were related to increased pain which tended to persist longer than normal. Trait anxiety also correlated with simple analgesic consumption, and neuroticism was weakly associated with Omnopon requirements. Thus, regular analgesics prescribed for at least 3 days will anticipate the needs of such patients. Despite higher levels of anxiety and neuroticism, women did not complain of more pain or require more analgesia than men in this study. There was also no overall correlation between post-operative pain experience and analgesic requirements. Therefore analgesic tablet consumption cannot be used as a measure of pain control.

Stabilisation of collagen by betel nut polyphenols as a mechanism in oral submucous fibrosis

Treatment of reconstituted collagen fibrils and pieces of rat dermis with the crude extract, purified tannins or (+)-catechin from betel nut (Areca catechu) increases their resistance to both human and bacterial collagenases in a concentration-dependent manner. These tanning agents may stabilise collagen in vivo following damage to the oral epithelium, and promote the sub-epithelial fibrosis which occurs in betel nut chewers.

Stimulation of human fibroblast collagen synthesis in vitro by gamma-aminobutyric acid

Human buccal mucosa fibroblasts were exposed in culture to gamma-aminobutyric acid (GABA) and the areca alkaloid arecaidine. Both GABA and arecaidine stimulated collagen synthesis and proliferation in a concentration-dependent manner, with arecaidine consistently producing the greater stimulation. Prior exposure to GABA or arecaidine for 5 days caused the cells to become insensitive when challenged with either drug.

Interleukin-1-like activity in capsular material from Haemophilus actinomycetemcomitans

This paper describes the activity of a bacterial surface component (capsular material, CM) in biological assays for interleukin-1 (IL-1). CM from the periodontal pathogen Haemophilus actinomycetemcomitans was tested in the following in vitro assays: mouse thymocyte proliferation (LAF assay), stimulation of collagenase and prostaglandin (PG) E2 synthesis by articular chondrocytes, and stimulation of PGE2 synthesis by fibroblasts. In all these assays, CM gave a response similar to an IL-1 preparation. This ability to mimic IL-1 suggests an important role for CM in both cell-mediated immunity and connective tissue destruction in localized juvenile periodontitis (LJP).

An in-vitro comparison of human fibroblasts from normal and oral submucous fibrosis tissue

Fibroblasts cultured in vitro from normal buccal tissue and from tissue from oral submucous fibrosis (OSF) associated with betel-nut chewing showed no significant difference in their rates of proliferation in culture, nor in the rate at which they hydrolysed the betel nut alkaloid arecoline to arecaidine. Basal rates of collagen synthesis were slightly higher in the OSF cells but, on addition of arecoline, the rate of collagen synthesis in normal and OSF cells was stimulated to the same level.

Inhibition of fibroblast proliferation and collagen synthesis by capsular material from Actinobacillus actinomycetemcomitans

Cytotoxic effects of bacteria found in dental plaque are usually attributed to lipopolysaccharides (LPS) or ill-defined toxins. Many bacteria implicated in periodontal disease produce surface exopolymers (capsules) recently shown to stimulate bone resorption. Capsular material and LPS extracted from Actinobacillus (Haemophilus) actinomycetemcomitans were purified and examined for their effects on cultures of human gingival fibroblasts. DNA and collagen synthesis were significantly inhibited by capsular material (0.1-50 micrograms/ml). LPS caused only modest inhibition of DNA synthesis at 10 and 50 micrograms/ml, and had no effect on collagen synthesis. Release of lactate dehydrogenase from fibroblasts was not increased by LPS nor by capsular material, showing that the inhibitory effects were not due to cell death. Capsular material, but not LPS, caused a pronounced increase in cell size; a doubling of the nuclear area occurred within 72 h exposure. These results indicate that the capsule of A. actinomycetemcomitans may play an active role in the tissue destruction characterising inflammatory periodontal disease.

In vitro inhibition of lipopolysaccharide-induced bone resorption by polymyxin B

Lipopolysaccharide (LPS) purified from Haemophilus actinomycetemcomitans stimulates resorption and inhibits collagen synthesis in mouse calvaria bones in vitro. Addition of polymyxin B caused a dose-related inhibition of LPS-stimulated bone resorption and reversal of the inhibition of collagen synthesis. A polymyxin B to LPS ratio of 2:1 prevented bone resorption and restored collagen synthesis to control levels. The activity of polymyxin B was specific for LPS as bone resorption induced by prostaglandin E2 or parathyroid hormone was unaffected at similar concentrations. These results indicate that polymyxin B and its analogues may have potential in the treatment of periodontal disease by reducing bone loss induced by lipopolysaccharides.