Bilateral arthrodesis of the distal tibiofibular joint for deforming osteochondromatas.

The first case of bilateral distal tibiofibular joint fusions for osteochondromas is reported with excellent long-term outcomes.

Clinical and radiographic features of solitary and cemento-osseous dysplasia-associated simple bone cysts.

UNLABELLED: The simple bone cyst (SBC) is a pseudocyst that can occur as a solitary entity in the jaws or may occur in association with cemento-osseous dysplasia (COD). OBJECTIVE: The purpose of this study was to review the clinical and radiographic features of solitary and COD-associated SBCs. METHODS: Archived imaging reports from the Special Procedures Clinic in Oral and Maxillofacial Radiology at the Faculty of Dentistry at the University of Toronto between 1 January 1989 and 31 December 2009 revealed 23 COD-associated SBCs and 68 solitary SBCs. RESULTS: Almost all solitary and COD-associated SBCs were found in the mandible. Furthermore, 87.0% of COD-associated SBCs were found in females in their fifth decade of life (P < 0.001) while solitary SBCs were found in equal numbers in both sexes in their second decade of life (P < 0.005). COD-associated SBCs were also more likely to cause thinning of the endosteal cortex, bone expansion and scalloping of the superior border between teeth (all P < 0.001) than solitary SBCs that are classically described as having these characteristics. Finally, COD-associated SBC demonstrated a loss of lamina dura more often (P < 0.05) than solitary SBCs. CONCLUSIONS: Knowledge of the sporadic association between COD and SBC and their potential radiographic appearances should prevent inappropriate treatment and management of these patients.

Prognostic assessments of medical therapy and vestibular testing in post-traumatic migraine-associated dizziness patients.

OBJECTIVE: The aim of this study was to characterize our clinical population of patients suffering with post-traumatic migraine-associated dizziness (PTMAD) and determine any associations with medical interventions and vestibular testing metrics to help predict response to treatments. STUDY DESIGN: Retrospective chart review. SETTING: Tertiary referral center. SUBJECTS AND METHODS: The electronic medical records of 83 patients presenting to a tertiary referral center who were given a diagnosis of PTMAD and who had been treated were retrospectively reviewed. General characteristics, clinical treatment, pre- and post-vestibular therapy testing metrics, and success and failure outcomes were assessed. Patients were assigned into responder and nonresponder groups related to their headaches and evaluated at two specific time points. Medication failures and vestibular test metrics were compared to identify and predict clinical outcomes. RESULTS: Seventy-two of 82 patients (88%) were analyzed at two time points. Use of verapamil, topiramate, gabapentin, amitryptiline, and valproic acid showed no comparative treatment benefit in responders compared to nonresponders (P = 0.294). Findings associated with successful treatments include response to initial medication (P = 0.001), final dynamic gait index (DGI) scores (P = 0.029), final vertical dynamic visual acuity test (DVAT) scores (up, 0.007; down, 0.006), and both final and change in computerized dynamic posturography-sensory organization test (CDP-SOT) scores (P = 0.001, P = 0.032). The antipsychotic quetiapine was specifically associated with outcome failures (P = 0.003). CONCLUSION: Specific prophylactic antimigraine medications were not associated with improved outcomes in PTMAD patients. Initial clinical responses and vestibular test metrics may guide physicians to predict successful outcomes.

Steroid receptor coactivator-2 expression in brain and physical associations with steroid receptors.

Estradiol and progesterone bind to their respective receptors in the hypothalamus and hippocampus to influence a variety of behavioral and physiological functions, including reproduction and cognition. Work from our lab and others has shown that the nuclear receptor coactivators, steroid receptor coactivator-1 (SRC-1) and SRC-2, are essential for efficient estrogen receptor (ER) and progestin receptor (PR) transcriptional activity in brain and for hormone-dependent behaviors. While the expression of SRC-1 in brain has been studied extensively, little is known about the expression of SRC-2 in brain. In the present studies, we found that SRC-2 was highly expressed throughout the hippocampus, amygdala and hypothalamus, including the medial preoptic area (MPOA), ventral medial nucleus (VMN), arcuate nucleus (ARC), bed nucleus of the stria terminalis, supraoptic nucleus and suprachiasmatic nucleus. In order for coactivators to function with steroid receptors, they must be expressed in the same cells. Indeed, SRC-2 and ER(alpha) were coexpressed in many cells in the MPOA, VMN and ARC, all brain regions known to be involved in female reproductive behavior and physiology. While in vitro studies indicate that SRC-2 physically associates with ER and PR, very little is known about receptor-coactivator interactions in brain. Therefore, we used pull-down assays to test the hypotheses that SRC-2 from hypothalamic and hippocampal tissue physically associate with ER and PR subtypes in a ligand-dependent manner. SRC-2 from both brain regions interacted with ER(alpha) bound to agonist, but not in the absence of ligand or in the presence of the selective ER modulator, tamoxifen. Analysis by mass spectrometry confirmed these ligand-dependent interactions between ER(alpha) and SRC-2 from brain. In dramatic contrast, SRC-2 from brain showed little to no interaction with ERbeta. Interestingly, SRC-2 from both brain regions interacted with PR-B, but not PR-A, in a ligand-dependent manner. Taken together, these findings reveal that SRC-2 is expressed in brain regions known to mediate a variety of steroid-dependent functions. Furthermore, SRC-2 is expressed in many ER(alpha) containing cells in the hypothalamus. Finally, SRC-2 from brain interacts with ER and PR in a subtype-specific manner, which may contribute to the functional differences of these steroid receptor subtypes in brain.

Nuclear Thimet oligopeptidase is coexpressed with oestrogen receptor alpha in hypothalamic cells and regulated by oestradiol in female mice.

Thimet oligopeptidase (EC 3.4.24.15; also called EP24.15 and TOP; referred to here as TOP) is a neuropeptidase involved in the regulation of several physiological functions including reproduction. Among its substrates is gonadotrophin-releasing hormone (GnRH), an important hypothalamic hormone that regulates the synthesis and release of oestradiol and facilitates female sexual behaviour. Using immunohistochemistry, we found that TOP is expressed in the nucleus of cells throughout the female mouse brain, and in high levels in steroid-sensitive regions of the hypothalamus, which is consistent with previous findings in male rats. Furthermore, dual-label immunofluorescence revealed that TOP and oestrogen receptor alpha (ERalpha) coexpress in several reproductively-relevant brain regions, including the medial preoptic area (mPOA), arcuate nucleus (ARC), ventrolateral portion of the ventromedial hypothalamic nucleus (VMNvl) and the midbrain central grey (MCG). Previous studies in rats have shown that oestradiol decreases hypothalamic TOP levels or activity, possibly potentiating the effects of GnRH. In the present study, analysis by immunohistochemistry revealed that oestradiol decreased TOP immunoreactivity in the VMNvl, whereas no differences were detected in the mPOA, ARC or median eminence. Overall, the present findings indicate that TOP is coexpressed with ERalpha, and oestradiol regulates TOP expression in a brain region-specific manner in female mice, providing neuroanatomical evidence that TOP may function in reproductive physiology and/or behaviour.

Vascular malformation of the temporomandibular joint: report of a case and review of the literature.

The diagnosis and treatment of vascular anomalies is extremely challenging because of inconsistent terminology and classification systems, as well as nonspecific clinical and radiological findings. We report a vascular malformation that was treated successfully via resection, and reconstructed using a custom-made temporomandibular joint fossa and condylar prosthesis by TMJ Concepts. The available pertinent literature is also reviewed.

Non-specific antiviral activity of antisense molecules targeted to the E1 region of human papillomavirus.

Antisense phosphorothioate oligonucleotides (ODN1 0x5 OMe) directed against the E1 start region of human papillomavirus 11 (HPV11) can inhibit papillomavirus induced growth of implanted human foreskin in a mouse xenograft model. Administration of a mismatch control oligonucleotide (ODN9 0x5 OMe), in which guanine was replaced with adenine in the same model, had no effect on papilloma induced growth. However, the apparent antiviral activity of ODN1 0x5 OMe was also shown in a lethal mouse cytomegalovirus (CMV) model, in which the oligonucleotides are not expected to have antisense activity. To understand the mechanisms of action of these oligonucleotides, a mismatch oligonucleotide (ODN61 0x5 OMe) was prepared which retained the CpG motifs of ODN1 0x5 OMe. This was tested in the mouse xenograft model and shown to have moderate inhibitory activity. As a definitive experiment, a comparison was made between the efficacy of the active oligonucleotide ODN1 0x5 OMe against two papilloma viruses HPV11 and HPV40. Both these viruses cause benign genital warts, but differ by four bases in their E1 sequence that was the target for ODN1 0x5 OMe. Papillomavirus induced growth in the mouse xenograft model was inhibited by ODN1 0x5 OMe in both cases, suggesting that oligonucleotide molecules have a non-specific antiviral activity that is not directly related to their antisense sequence.

An investigation of occupational metal exposure in thermal spraying processes.

A cross-sectional study of 34 workers engaged in thermal spraying at six worksites was undertaken in order to determine levels of exposure to and uptake of metals during different metal spraying activities. Levels of exposure to cobalt, chromium and nickel were highest in plasma sprayers and, on occasions exceeded UK Occupational Exposure Limits. Exposure to metals during detonation gun and electric arc spraying was better controlled and levels remained below the relevant Occupational Exposure Limits throughout the study period. Urinary levels of cobalt and nickel mirrored the airborne concentrations and the highest urine concentrations were again found in plasma sprayers. Urinary chromium levels were highest in electric arc sprayers, which may also reflect an increased body burden in this group due to a longer history of exposure. The findings clearly indicate that exposure to and uptake of metals may exceed UK Occupational Limits or Standards when spraying is performed manually or semi-automatically and where control relies on local exhaust ventilation (LEV) and personal respiratory protective equipment (RPE).

Characterization of hemolytic and cytotoxic Gallysins: a relationship with arylphorins.

Gallysin-1, an inducible effector protein in the protective response of Galleria mellonella larvae is a 75 kDa component of hemolytically active material (HAM) isolated from immune cell-free hemolymph. The sequence of the first 20 N-terminal amino acids of the antibacterial protein Gallysin-1 is identical to the predicted sequence of the first 20 amino acids of the Galleria arylphorin Lhp76 (larval hemolymph protein 76). A murine monoclonal antibody to the 20 amino acid N-terminal peptide of Gallysin-1 (GYPQYHYDVETRKLDPSLVN) provides additional evidence for a link between Gallysin-1 and Lhp76, and is used to characterize HAM further. HAM, initially characterized as a mixture of two proteins, Gallysin-1 and a 69 kDa component is now identified as a 450-500 kDa heteromultimer, designated Gallysin. In vivo levels of Gallysin rise during the effector phase of an induced immune response. The monoclonal antibody inhibits the hemolytic activity of Gallysin. In addition to a hemolytic activity for mammalian erythrocytes, Gallysin possesses a cytotoxic activity for the human tumor cell line, K562. Lipopolysaccharides (LPS) and a Pseudomonas aeruginosa vaccine induce a cytotoxic activity which reaches its maximum levels in the hemolymph early (2 hours post-vaccination) in the protective response. The partially purified cytotoxic material (Cyt-M) obtained from cell-free hemolymph collected 2 hours after vaccination has hemolytic activity and shows structural similarities to Gallysin and Lhp76. The previously established role of Gallysin-1 as an effector protein in the protective response of Galleria mellonella indicates that arylphorins may play a role in insect immune responses.

Identification of antigenic sites on staphylococcal enterotoxin B and toxoid.

The staphylococcal enterotoxins (SEs) are capable of causing both food poisoning and a toxic shock-like illness in man. In addition, SEs are known to act as superantigens, stimulating T-cells according to their T-cell receptor Vbeta type. Relatively little is known of their antigenic determinants and how these may relate to the structure and function of the toxins. As a step in the study of these relationships, the entire molecule of SEB was synthesized in duplicate as a series of octapeptides overlapping by seven residues. This series thus represented all the potential linear epitopes of eight residues or less. The reactivity of the octapeptide series with antisera raised to purified SEB and to formaldehyde-inactivated SEB has been used to locate several antigenic sites on native SEB and to identify antigenic differences in the toxoid. Three antigenic peptides identified from the antigenic profile were synthesized and characterized. These represented amino acids 21-32, 93-107 and 202-217 of SEB. None of these peptides affected SEB-induced T-cell proliferation. However, the occurrence or absence of cross-reactivity of these peptides with antibodies to native SEB corresponds to the degree of exposure and/or the rigidity of these regions within SEB.

Inhibition of intracellular pH control and relationship to cytotoxicity of chlorambucil and vinblastine.

The uptake and cytotoxicity of weakly acidic or basic chemotherapeutic agents is determined in part by passive diffusion along the pH gradient between the intracellular and extracellular compartments. In vivo it is known that tumour extracellular pH is more acidic than intracellular pH. Using CaNT murine tumour cells in vitro, we found the cytotoxicity of chlorambucil (a weak acid) increased as the extracellular pH of the culture medium (pHmed) was acidified. The cytotoxicity of vinblastine shows a reverse pH relationship with reduced cytotoxicity as pHmed was acidified. Chlorambucil cytotoxicity increased at acidic pHmed because the weak acidic function is ionised to a lesser extent at acidic pH and, therefore, favours drug uptake into the relatively neutral intracellular compartment. Vinblastine cytotoxicity decreased at acidic pHmed because the weak basic function is ionised to a greater extent at acidic pH and therefore does not favour drug uptake into the relatively neutral intracellular compartment. Using a combination of an inhibitor of the cell membrane proton pump, amiloride, and the ionophore, nigericin, the intracellular compartment can be acidified. This results in a time-dependent increase in sensitivity of the cells to low pHmed with significant cytotoxicity after 6 h exposure to pHmed = 6.2 and suggests that there is potential for direct tumour cytotoxicity in vivo if the tumour extracellular pH were equally acidic. An indirect effect of intracellular acidification is to alter the distribution of drugs between the extra- and intracellular compartment by reducing the pH gradient across the cell membrane. In response to intracellular acidification, the cytotoxicity of chlorambucil was reduced and that for vinblastine was increased. Inhibition of cellular pH control may result in direct cytotoxicity by acidification due to inhibition of proton efflux or indirectly by resulting in differential uptake of chemotherapeutic agents with weak acidic or basic functions.

Enhancement of chlorambucil cytotoxicity by combination with flavone acetic acid in a murine tumour.

Previous studies using murine tumours have shown enhanced action of certain chemotherapeutic compounds when combined with agents that reduce tumour blood flow. In the majority of cases the compounds used were cytotoxic to the induced hypoxic cells but in this study we have investigated the relative importance of changes in tumour pH following blood flow reductions. The role of tumour pH was investigated by using combinations of the cytotoxic alkylating agent Chlorambucil (CHL) with the vascular occluding agent Flavone Acetic Acid (FAA). Chlorambucil is a weak acid (pKa = 3.7) and is concentrated within cells exposed to culture media at low pH or to the acidic microenvironment in vivo. In vitro incubations showed that greater cytotoxicity was obtained when cells were incubated at low pH and that the cytotoxicity was independent of the level of oxygenation at the time of the drug incubation. Combination of both CHL and FAA in vivo resulted in greater reductions in cell survival and growth delay than when either agent was given alone. Simultaneous administration of the two agents were very effective, potentially due to two factors; firstly, that the pH of the tumour changes during ischaemia and secondly, that the reduced blood flow potentially alters the pharmacokinetic distribution of CHL resulting in 'drug-trapping' within the tumour. Since the action of CHL is independent of the induced hypoxia which results from blood flow reduction it is suggested that the increased in vivo action is due in part to the changes in tumour pH.

Ischaemia induced cell death in tumors: importance of temperature and pH.

PURPOSE: Increasing attention has focussed on the therapeutic potential of agents which can reduce tumor blood flow and induce ischaemia for long enough to result in tumor cell death. A confounding factor in this approach is the fact that the core temperature of superficial tumors reduces when the supplying blood flow is occluded and therefore protects the tumor cells from "metabolic" death. Consequently, we have tested the importance of tumor temperature on the relationship between vascular occlusion and cell death. METHODS AND MATERIALS: The murine tumor CaNT used in this study was implanted subcutaneously in the dorsum. Total vascular occlusion was achieved by physically occluding the blood supply to the tumors for periods between 1 and 20 h. The mouse temperature was controlled by placing the whole body in a thermostatically controlled incubator maintained at 35 degrees C. Tumor cell survival was assessed using an excision assay and by measuring the delay in growth of treated tumors. Measurement of tumor pH was achieved using microelectrodes. RESULTS: The core temperature of unclamped tumors was approximately 33 degrees C, but fell by about 5 degrees C during vascular occlusion at room temperature. Tumor cell survival was decreased with increasing periods of vascular occlusion at room temperature, but a greater reduction in cell survival and correspondingly increased regrowth delay was observed when the tumor temperature was prevented from cooling below preocclusion values. The extracellular pH (pHe) fell during vascular occlusion and this reduction was greater when the tumor temperature was maintained at preocclusion values. This extracellular acidosis is expected to partly explain the observation of greater tumor cell death in those tumors whose temperature does not reduce during occlusion. CONCLUSION: The temperature of superficial tumors reduces in response to vascular occlusion. This may result in an underestimation of the cytotoxicity of agents which reduce tumor blood flow as the tumor cooling protects the cells from the acidosis that accumulates within the occluded tumor.

Antiandrogen action in the development of androgen insensitivity in S115 mouse mammary tumour cells.

Endocrine therapy for steroid-sensitive tumours often involves administration of steroid antagonists which are designed to bind to the steroid receptor and block steroid action. However, the clinical problem remains the temporary nature of the tumour regression. Since in vitro models suggest that steroid ablation itself can result in loss of steroid sensitivity of tumour cells, these studies aimed to investigate the influence of the antiandrogen ICI 141,307 on this progression. This antiandrogen exhibits both agonist and antagonist actions on androgen-regulated cellular and molecular parameters of S115 mouse mammary tumour cells in culture. Its ability to regulate mouse mammary tumour virus (MMTV) RNA production in these cells confirms that the antiandrogen-receptor complex can not only bind to the steroid response element (SRE) in the MMTV DNA sequences but also activate gene transcription. Despite these molecular abilities of this antiandrogen, it was still unable to maintain androgen sensitivity in the long term. It was able to delay progression to insensitivity of the various steroid-regulated parameters, although the different parameters were delayed for different lengths of time, but ultimately the antiandrogen was unable to prevent loss of any parameters. It is thus concluded that the nature of the ligand is critical for maintenance of steroid sensitivity: only androgen and not antiandrogen will maintain long-term response. Previous molecular models for loss of steroid response suggest that it could result from inactivation of SRE in the genome when no receptor complex is bound. However, loss of response occurred in these experiments even in the presence of an activated receptor complex capable of binding to the SRE. Possible molecular mechanisms and the clinical implications are discussed.

Effects of selected carbohydrates and the contribution of the prophenoloxidase cascade system to the adhesion of strains of Pseudomonas aeruginosa and Proteus mirabilis to hemocytes of nonimmune larval Galleria mellonella.

The adhesion of strains of Pseudomonas aeruginosa and Proteus mirabilis to the plasmatocytes and granular cells of nonimmune larval Galleria mellonella was influenced by and varied with the type of carbohydrate. Laminarin enhanced prophenoloxidase activation and bacterial adhesion to the hemocytes whereas sucrose suppressed both activities. For all other sugars there was no correlation between bacterial adhesion to the hemocytes and phenoloxidase activity. It is proposed that bacterial adhesion to the hemocytes may be mediated by both lectinlike binding and components of the prophenoloxidase activating system acting like opsonins.

Studies on the cellular location, physical properties and endogenously attached lipids of acylated proteins in human squamous-carcinoma cell lines.

The location of cell proteins with covalently attached lipid was examined in two human squamous-carcinoma cell lines. Cells were labelled with either palmitic acid or myristic acid and disrupted by sonication, followed by differential centrifugation of the cell lysates. SDS/polyacrylamide-gel electrophoresis of the resulting cell fractions indicated that most of the palmitate-labelled proteins were found in cell membranes, whereas most of the myristate-labelled proteins were found in the cytosol, although some were located in cell membranes. Experiments with lipid-labelled proteins extracted with the phase-separable detergent Triton X-114 showed that palmitate-labelled proteins behaved as hydrophobic proteins, partitioning into the lower phase of the detergent, whereas most of the myristate-labelled proteins remained in the upper phase. Although one of these cell lines expressed large amounts of epidermal-growth-factor receptor, this could not be labelled by either myristic acid or palmitic acid, whereas transferrin receptor was labelled by palmitic acid. The lipids normally attached to cell proteins in these two human squamous-carcinoma cell lines were characterized by labelling the cells with [3H]acetate. The labelled cell proteins were exhaustively extracted with organic solvents, and subjected to sequential alkaline and acid hydrolyses to release the attached lipids, which were then analysed by h.p.l.c. Most of the lipid released by the alkaline treatment chromatographed as palmitic acid or stearic acid, whereas the subsequent acid treatment released myristic acid as well as some palmitic acid and stearic acid. No other fatty acids apart from these were found attached to cell proteins.

Studies on the attachment of myristic and palmitic acid to cell proteins in human squamous carcinoma cell lines: evidence for two pathways.

The ability of human keratinocytes and squamous carcinoma cell lines to attach lipid covalently to cell proteins has been examined using both palmitic and myristic acids. SDS-polyacrylamide gel analyses of the proteins labelled with these lipids demonstrated that each labelled a different set of proteins. Covalently protein bound palmitic acid could be removed from the proteins by mild alkali hydrolysis but the bound myristic acid required prolonged acid hydrolysis to release it from the associated proteins. H.p.l.c. analyses of the released lipid confirmed that both lipids were attached to proteins directly and that the labelling was not due to the lipids being catabolised. Cycloheximide could prevent the attachment of myristic acid to cell proteins, but only reduced the levels of palmitic acid incorporation. Pulse chase experiments indicated that there was little turnover of the attached myristic acid whereas this was significant for covalently bound palmitic acid. These observations show for the first time that two different protein populations are labelled by different lipids in eukaryotic cells, and that there appear to be two separate pathways for the acylation of proteins in such cells.

Auricular calcification.

Auricular calcification in two patients was discovered by palpation and x-ray of the pinnae of the ears. In one patient auricular calcification was locally secondary to chronic inflammation, while in the other patient systemically secondary to adrenal insufficiency, a systemic factor.