Correlation between changes in the gonial area and postoperative stability in the treatment of mandibular prognathism.

INTRODUCTION: The present study was to investigate the relationship between the post-operative area of the gonial region (lateral and frontal) and post-operative relapse. MATERIAL AND METHODS: Thirty-seven patients, treated for mandibular prognathism were followed with serial lateral cephalograms [pre-operatively (T1), immediately after surgery (T2), and at least 2 years post-operatively (T3)]. The surgical changes (T21), post-operative stability (T32) and 2-year surgical change (T31) were evaluated by the Student's t-test. Pearson's correlation coefficient analysis was used to determine the correlations between the cephalometric parameters. Multiple linear regression analysis was used to assess the association between the risk factors and post-operative relapse. RESULTS: The immediate post-operative changes (T21), mean setback of the Me was 12.3 mm and the frontal gonial area (T2) was increased by 138.7 mm2. The final post-operative changes (T31), lateral gonial area was significantly reduced by 190.5 mm2. CONCLUSION: Relapse was significantly correlated with the amount of setback. However, changes in the area of the gonial region (lateral and frontal) showed weak correlation with relapse. Multiple regression analysis also showed poor predictability of relapse. In conclusion, the results of this study showed that significant changes in the area of the gonial region (lateral and frontal) did not affect the maintenance of post-operative stability.

Radiobiological rationale and clinical implications of hypofractionated radiation therapy.

Recent clinical trials of hypofractionated radiation treatment have provided critical insights into the safety and efficacy of hypofractionation. However, there remains much controversy in the field, both at the level of clinical practice and in our understanding of the underlying radiobiological mechanisms. In this article, we review the clinical literature on hypofractionated radiation treatment for breast, prostate, and other malignancies. We highlight several ongoing clinical trials that compare outcomes of a hypofractionated approach versus those obtained with a conventional approach. Lastly, we outline some of the preclinical and clinical evidence that argue in favor of differential radiobiological mechanisms underlying hypofractionated radiation treatment. Emerging data from the ongoing studies will help to better define and guide the rational use of hypofractionation in future years.

Intraoral approach for arthroplasty for correction of TMJ ankylosis.

This study evaluates the authors' technique using the intraoral approach for the management of temporomandibular joint (TMJ) ankylosis. The technique was used on 16 TMJs in 14 patients with a mean age of 28.5 years; their average postoperative mouth-opening was 33.7 mm. All the patients had Sawhney's type IV TMJ ankylosis except a child with type I. One patient had recurrent ankylosis and was managed using the same intraoral approach again. Average follow-up was 56 months. The protocol consists of interpositional arthroplasty via an intraoral approach and aggressive mouth-opening exercises. An intraoral incision is made over the buccal shelf and the soft tissue of the mandibular ramus reflected. Osteotomy is carried out at the coronoid process and adequate osteotomy is accomplished at the level of the condylar neck. Adequate gap osteotomy at the ankylosed condyle is performed and followed by placement of the interpositional material, such as rib cartilage, masseter, buccal fat pad and costochondral graft. The wound is then closed meticulously. The advantages of this intraoral approach are excellent cosmetic appearance with no facial scar, lower risk of injury to the facial nerve or auriculotemporal nerve and no salivary fistula formation.

A case of tumoural calcinosis in the temporomandibular joint associated with systemic sclerosis.

Systemic sclerosis (SSc) is a relatively rare condition characterized by the excessive production and deposition of collagen within tissue. This condition is thought to be immunologically mediated and, in addition to its notorious cutaneous manifestations, often involves multiple organs. A case is presented of systemic sclerosis associated with extensive tumoural calcinosis in the temporomandibular joint. There has been no evidence of recurrence or complications during approximately 2 years of follow up, but long-term follow up is essential.

Malignant pleural effusions due to small-cell lung carcinoma: a cytologic and immunocytochemical study.

Patients with small-cell lung carcinoma (SCLC) rarely present with pleural effusions. Based on morphology alone, recognition of SCLC in effusion cytology may be challenging because of the resemblance of neoplastic cells to lymphocytes. Immunocytochemistry may be helpful in its diagnosis. The objective of this study was to review the morphology and evaluate the use of immunocytochemistry in diagnosing SCLC in pleural fluids. Patients with SCLC who presented with pleural effusions were identified during a 6-yr period. The cytology and medical records were reviewed. Formalin-fixed, paraffin-embedded cell blocks of fluid specimens were immunostained with neuroendocrine markers (chromogranin A and synatophysin), cytokeratin 20 (CK20), and thyroid transcription factor-1 (TTF-1). The latter is a nuclear transcription protein that is expressed in normal respiratory epithelium and also in more than 90% of SCLCs. Of the 256 patients diagnosed with SCLC during the study period, 8 (2.7%) patients (3 females and 4 males, age range from 56-85 yr) also developed pleural effusions. One patient had 2 fluid specimens during the course of their disease, giving a total of 9 specimens. Four specimens had a positive cytologic diagnosis of SCLC, and 2 were initially diagnosed as suspicious for SCLC. The remaining 3 specimens were negative for SCLS. The specimens with a positive or suspicious diagnosis showed single and aggregates of small to medium-sized single cells with a high nuclear:cytoplasmic (N:C) ratio, round to angulated nuclei, and salt-and-pepper chromatin. Nuclear molding was also noted. Five out of 6 (83%) specimens with a positive or suspicious diagnosis of SCLC were positive for both chromogranin A and TTF-1. Synaptophysin was positive in 3 of 6 (50%) positive or suspicious cases. None of the cases were positive for CK20. All cases with a negative cytologic diagnosis were negative for chromogranin A, synatophysin, CK20, and TTF-1. In conclusion, patients with SCLC rarely present with pleural effusions. The cytology of SCLC is characteristic. The use of immunocytochemistry, particularly with antibodies to chromogranin A, TTF-1, and CK 20, aids in the differential diagnosis.

Use of a panel of markers in the differential diagnosis of adenocarcinoma and reactive mesothelial cells in fluid cytology.

To evaluate the use of a panel of markers to differentiate adenocarcinoma and the reactive/inflammatory process in fluid cytology, we stained 29 formalin-fixed, paraffin-embedded cell blocks of effusion fluid from patients with metastatic adenocarcinoma and 24 cell blocks from patients with benign effusion with mucicarmine and antibodies to carcinoembryonic antigen (CEA), B72.3, and calretinin. Positive staining with CEA, B72.3, and mucicarmine was seen in 22 (76%), 20 (69%), and 18 (62%) adenocarcinoma cases, respectively. All except 1 adenocarcinoma was negative for calretinin. No benign cases were positive for B72.3 and mucicarmine. In 1 benign case, scattered epithelial cells demonstrated weak positivity for CEA. The majority of combinations were 100% specific for adenocarcinoma. The highest sensitivity (86%) for adenocarcinomas was achieved with the staining combination of negative for calretinin and positive for any adenocarcinoma marker (CEA, B72.3, or mucicarmine). The use of a panel of markers that recognize adenocarcinoma and mesothelial cells is useful in the differential diagnosis between metastatic adenocarcinoma and the reactive/inflammatory process. The profile of positive staining with at least one of the adenocarcinoma markers and negative calretinin staining is highly specific and sensitive for identifying adenocarcinoma in fluid cytology.

An immunochemical study on tau glycation in paired helical filaments.

Glycation is a non-enzymatic posttranslational modification that involves a covalent linkage between a sugar and an amino group of protein molecule forming ketoamine. Subsequent oxidation, fragmentation and/or crosslinking of ketoamine leads to the production of advanced glycation endproducts (AGEs). Formation of AGEs causes detrimental effects on the structure and function of affected proteins. Accumulation of AGEs has been implicated in normal aging and in the pathogenesis of diabetes-associated complications and Alzheimer's disease (AD). Of all AGEs, Nepsilon-(carboxymethyl)lysine (CML) is a major glycoxidation product known to be stable and accumulate progressively in vivo. In order to determine if tau is glycated in AD, we raised a rabbit antibody to CML that demonstrated its usefulness in detecting glycation of different proteins in vitro, including BSA, ribonuclease, lysozyme and recombinant tau. Immunochemical analyses indicated that ribose and glucose-6-phosphate are more effective than glucose in generating CML formation in these proteins. We used this antibody to probe for glycation in the following human tau preparations: tau of normal brains and preparations of soluble PHF-tau as well as insoluble PHF from AD brains. All three principal tau components resolved from PHF-tau on Western blots showed CML immunoreactivity indicating that tau is glycated in PHF-tau; and insoluble PHF exhibited prominent CML immunoreactivity on top of the stacking gel. Moreover, immunoelectron microscopic analyses indicate that the anti-CML antibody labels predominantly PHF in aggregates. Taken together, these results suggest that tau becomes glycated in PHF-tau and glycation may play a role in stabilizing PHF aggregation leading to tangle formation in AD.

Mechanism of crosslinking of proteins by glutaraldehyde III. Reaction with collagen in tissues.

Bovine pericardium, a dense collagenous connective tissue, was crosslinked with glutaraldehyde using different modalities of fixation. The degree of crosslinking was evaluated as a function of the ability of CNBr and pronase to solubilize collagen. Our results suggest that glutaraldehyde fixes primarily the surface of the fibers and creates a polymeric network which hinders the further crosslinking of the interstitium of the fiber. When a low concentration of glutaraldehyde was used, a slow time-dependent crosslinking process was observed. This slow process is maintained over a long period of time, greatly beyond that required for the actual penetration of glutaraldehyde to occur.