IL-17 attenuates the anti-apoptotic effects of GM-CSF in human neutrophils.

Interleukin (IL)-17A is a pleiotropic, pro-inflammatory cytokine that is implicated in chronic inflammatory and degenerative disorders. IL-17 has been demonstrated to link activated T-lymphocyte with the recruitment of neutrophils at sites of inflammation, however whether IL-17 can mediate neutrophil survival and subsequently affect inflammatory responses has not fully been elucidated. In our study, we demonstrate that human peripheral blood and HL-60 differentiated neutrophils express mRNA and cell surface IL-17A receptor. IL-17A does not affect the rate of spontaneous neutrophil apoptosis, however significantly decreased granulocyte macrophage-colony stimulating factor (GM-CSF)-mediated survival by antagonizing the signal transduction pathways of p38, Erk1/2 and signal transducer and activator of transcription (STAT) 5B. These events were associated with reduced myeloid cell lymphoma-1 (Mcl-1) protein levels, increased translocation and aggregation of Bax to mitochondria, decreased mitochondrial transmembrane potential and in an increase in caspase-3/7 activity. These events were independent of increased Fas or soluble Fas ligand expression levels. Taken together, our findings suggest that IL-17 may regulate neutrophil homeostasis and favor the resolution of inflamed tissues by attenuating the delay in neutrophil apoptosis induced by inflammatory cytokines.

IgE modulates neutrophil survival in asthma: role of mitochondrial pathway.

The high-affinity IgE receptor (FcepsilonRI) has recently been reported to be expressed by neutrophils in atopic asthmatic individuals, leading to speculations that IgE could influence biological functions of these cells. In this study, we demonstrate that monomeric human IgE delayed spontaneous apoptosis of primary human neutrophils from atopic asthmatics in vitro. This effect was not dependent on FcepsilonRI cross-linking or autocrine release of soluble mediators; however, it was associated with increased expression of the antiapoptotic myeloid cell leukemia-1 protein, retention of the proapoptotic molecule Bax in the cytoplasm, decreased release of Smac from mitochondria, and reduced caspase-3 activity. Taken together, our results indicate that in vitro IgE can delay programmed cell death of neutrophils from allergic asthmatics and this may possibly contribute to neutrophilic inflammation in atopic asthma.

Use of amnion as a graft material in vestibuloplasty: a preliminary report.

OBJECTIVE: The aim of this study was to evaluate the clinical use of amnion as a biodegradable graft material for vestibuloplasty. STUDY DESIGN: Seven subjects who had been referred for preprosthetic surgery underwent mandibular vestibuloplasty using Clark's technique and amnion as graft material. Fresh amniotic membrane was placed in the area and an acrylic splint was used with soft liner and 0.4-mm wires to cover the surgical site. The area was reexamined after 1 week, 2 weeks, 4 weeks, 3 months, and 6 months. RESULTS: A white necrotic soft tissue layer could be seen with underlying hyperemic tissue and an average reduction of 1 to 3 mm in the depth of the labial vestibule after a week. By the end of the second week, the necrotic layer had disappeared, leaving slightly hyperemic mucosal tissue under. By the third week, the graft area could be noticed but the amnion had completely degenerated and disappeared. After 4 weeks, the subjects could be referred for their prosthodontic treatment. The reduction in the depth of the buccal vestibule ranged from 17% to 40% after 6 months' follow-up. CONCLUSION: Amnion might be used as a potential graft material for vestibuloplasty.

Histopathologic comparison of normal and hyperplastic condyles.

OBJECTIVE: The aim of this study was to compare normal and hyperplastic mandibular condyles using two different histopathologic staining techniques. STUDY DESIGN: Nine cases of condylar hyperplasia and 13 normal cases were studied after hematoxylin and eosin and silver staining. RESULTS: There was a significant difference between the two groups in the thickness of the hyperplastic cartilage layer of condylar soft tissue (P = 0.017). Also, the number of argyrophilic nucleolar organizer regions was significantly higher in the condylar hyperplasia case group (P = 0.0001). No significant differences could be demonstrated in cartilage island frequency, penetration depth, and distribution in the cancellous bone of condyles. CONCLUSION: The thickness of the hyperplastic cartilage layer appears significantly increased in condylar hyperplasia. In addition, argyrophilic nucleolar organizer region count may be useful in histopathological identification of condylar hyperplasia.

The effect of prostaglandin E2 and calcium gluconate on orthodontic tooth movement and root resorption in rats.

Possible modifications in orthodontic tooth movement (OTM) and root resorption as a result of local injections of prostaglandin E2 (PGE2) alone and with calcium gluconate (Ca) formed the aim of the present study. Twenty-four 8-week-old male Wistar rats were selected and randomly divided into three groups of eight. Both quadrants of the upper jaws of the first group of animals were used; therefore this group comprised two groups: control and normal. The upper left first molars of these eight animals were not placed under orthodontic force and received no injection, to serve as the normal group, considered for root resorption comparison only. The control group had localized submucosal injections of normal saline on the buccal side of the upper right first molar. In the third group, 0.1 ml of 1 mg/ml PGE2 was injected at the same site and the fourth group received an intraperitoneal injection of 200 mg/kg Ca (10%) in addition to the PGE2. All the injections were performed on days 0 and 7. The orthodontic appliance consisted of a closed coil spring ligated to the upper right first molar and incisor, exerting a force of 60 g during the 21-day experimental period, after which the animals were sacrificed. Palatal halves were removed for histological examination and for calculation of the amount of root resorption. Statistical analysis of data showed a significant (P < 0.05) acceleration in OTM after PGE2 injection compared with the control group. The addition of Ca reduced OTM but a significant increase (P< 0.05) was still recorded. A significant difference (P < 0.05) in root resorption was only observed between the PGE2 and normal groups. The findings show the importance of calcium ions working in association with PGE2 in stabilizing root resorption while significantly increasing OTM.

Nucleolar organizer regions in selected odontogenic lesions.

OBJECTIVE: The present study aimed to assess the usefulness of argyrophilic nucleolar organizer regions (AgNORs) as quantitative criteria in the diagnosis of odontogenic cysts and tumors. STUDY DESIGN: This descriptive cross-sectional study was done on archival paraffin blocks (n = 37), consisting of 10 conventional ameloblastomas, 7 cases of unicystic ameloblastoma, 10 odontogenic keratocysts, and 10 dentigerous cysts, all accessioned between 1994 and 2000. RESULTS: The findings showed a significant statistical difference among the 4 lesions (P <.001). Conventional and unicystic ameloblastomas had a significantly higher (P <.05) number of AgNORs than odontogenic keratocysts and dentigerous cysts. No significant differences were observed within each group of tumors or cysts. The number of AgNORs was also significantly higher (P <.005) in the nuclei of basal layer cells of the epithelial lining of keratocysts than in the nuclei of parabasal layer cells. AgNORs in conventional and unicystic ameloblastomas were smaller but more broadly distributed, which may indicate higher proliferative activity. CONCLUSION: AgNORs can be useful in the histopathologic differentiation of ameloblastomas from odontogenic cysts.