Finite Element Analysis: A Maxillofacial Surgeon’s Perspective

The science of finite element analysis (FEA) is purely a mathematical way of solving complex problems in the universe. In medical field, this is an innovation in biomedical research and development, as it gives easier mathematical solution to biological problems. This article deals with the understanding of various basic material properties of bone like Young’s modulus, yield strength, Bulk modulus, shear modulus, Poisson’s ratio and density from a maxillofacial surgeon’s perspective. Basic concepts in FEA, its application, advantages, disadvantages, and limitations in the field of maxillofacial surgery have been discussed. The importance of surgical fraternity to be in coordination with evolving technologies has been emphasized for the future of evidence based practice of oral and maxillofacial surgery.     

A study on coronal incision for treating zygomatic complex fractures

Objective  To study the value of coronal incisions for treating zygomatic complex fractures and evaluate the advantages, indications and complications associated with it. Method  In this prospective study, 12 patients were randomly selected regardless of age, sex requiring open reduction and internal fixation of communited zygomatic complex fractures with or without other associated fractures of the midface. Patients were all treated by coronal approach for open reduction and internal fixation of fracture of the zygomatic complex. Other local incisions were used if required. Results  In all cases postoperative complications were relatively minor except in one case were the temporal branch of facial nerve weakness persisted at 3 months. Whereas 5 cases reported with slight weakness of the temporal branch of the facial nerve which resolved at the end of 3 months. The time taken for exposure of the fracture site via the coronal incision had a mean of 28.7 minutes. There were no cases of flap infection and just 1 case of stitch abscess reported. The same case later reported with a hypertrophic scar formation of greater than 0.5cm at 3months. In all other cases scar formation was negligible and well hidden within the hairline. There were no reported cases of paraesthesia at the operated site or hollowing of the temporal fossa. Conclusion  The coronal incision provides excellent access to the zygomatic arch and zygomatic complex, aiding in good anatomical reduction and also has the added advantage of the scar hidden in the hairline. It also has disadvantages like long operating time, risk of facial nerve injury, scarring in patients with male pattern baldness, paraesthesia of operated site etc. Therefore the incision should be judiciously used and not overused and indications strictly applied.     

Therapy of human pancreatic carcinoma based on suppression of HMGA1 protein synthesis in preclinical models

Pancreatic carcinoma is one of the most aggressive tumors, and, being refractory to conventional therapies, is an excellent target for new therapeutic approaches. Based on our previous finding of high HMGA1 expression in pancreatic cancer cells compared to normal pancreatic tissue, we evaluated whether suppression of HMGA1 protein expression could be a treatment option for patients affected by pancreatic cancer. Here we report that HMGA1 proteins are overexpressed in pancreatic carcinoma cell lines, and their downregulation through an adenovirus carrying the HMGA1 gene in an antisense orientation (Ad Yas-GFP) results in the death of three human pancreatic carcinoma cell lines (PANC1, Hs766T and PSN1). Pretreatment of PANC1 and PSN1 cells with Ad Yas-GFP suppressed and reduced, respectively, their ability to form xenograft tumors in nude mice. To further verify the role of HMGA1 in pancreatic tumorigenesis, we used a HMGA1 antisense phosphorothioate oligodeoxynucleotide (ODN); its addition induced a decrease in HMGA1 protein levels and a significant reduction of the proliferation rate of PANC1-, Hs766T- and PSN1-treated cells. Therefore, suppression of HMGA1 protein synthesis by an HMGA1 antisense approach seems to be a feasible treatment strategy in pancreatic carcinomas.     

Admission hyperglycemia as a prognostic indicator in trauma

OBJECTIVE: The purpose of this study was to assess the utility of two levels of hyperglycemia as predictors for mortality and infectious morbidity in traumatically injured patients. METHODS: All patients >or= 17 years old presenting to a Level I trauma center as a "trauma alert" or a "trauma code" from January 1, 2000, through December 31, 2000, were reviewed. Hypoglycemic patients (glucose concentration < 70 mg/dL) were excluded (n = 4). Patients were considered hyperglycemic with an admission glucose concentration > 200 mg/dL (moderate hyperglycemia) or an admission glucose concentration in the upper quartile for the group (mild hyperglycemia [glucose concentration > 135 mg/dL]). RESULTS: Seven hundred thirty-eight patients were included in the study. Hyperglycemia was associated with increased mortality among both patients with moderate hyperglycemia (34.1% vs. 3.7%, p < 0.01) and those with mild hyperglycemia (15.5% vs. 2%, p < 0.01) compared with corresponding normoglycemic groups. Hyperglycemia proved to be an independent predictor of mortality and of hospital and intensive care unit length of stay after multiple logistic regression while controlling for age, Injury Severity Score, Revised Trauma Score, and gender. Infectious complications, including pneumonia (9.4% vs. 2%, p = 0.001), urinary tract infections (6.6% vs. 1.4%, p = 0.001), wound infections (4.9% vs. 0.6%, p = 0.039), and bacteremia (5% vs. 1.1%, p = 0.004), were significantly increased in patients with elevated glucose concentrations. Hyperglycemia is an independent predictor of increased infectious morbidity controlling for age, gender, and Injury Severity Score in multiple logistic regression models. CONCLUSION: Hyperglycemia independently predicts increased intensive care unit and hospital length of stay and mortality in the trauma population. It is associated with increased infectious morbidity. These associations hold true for mild hyperglycemia (glucose concentration > 135 mg/dL) and moderate hyperglycemia (glucose concentration > 200 mg/dL).     

Restoration of fragile histidine triad (FHIT) expression induces apoptosis and suppresses tumorigenicity in breast cancer cell lines

The fragile histidine triad (FHIT) gene at chromosome 3p14.2 is a tumor suppressor gene that is altered mainly by deletion in a large fraction of human tumors, including breast cancers. To evaluate the potential of FHIT gene therapy in this type of cancer, we have studied the biological effects of adenoviral FHIT transduction (Ad-FHIT) in breast cancer cell lines. The results showed that, after FHIT restoration in BT-549, MDA-MB-436, and HCC1806 cells, they underwent apoptosis by activation of the intrinsic pathway. In all three cell lines infected with Ad-FHIT, we have found activation of caspase-2, which is required for permeabilization of mitochondria, release of cytochrome c, and apoptosis. Furthermore, Fhit overexpression produces alteration in cell cycling properties, as well as reduction of the tumorigenic potential in nude mice.     

Aortic paraganglioma requiring resection and replacement of the aortic root

This case report demonstrates the resection of an aortic root paraganglioma incidentally discovered in a 32-year-old male with replacement of the root for an oncologically complete resection.     

Normal coronary artery dimensions in Indians

Background There is no available data on normal coronary artery size in the Indian population. We attempted to establish a database for normal dimensions of the coronary artery segments during life by using quantitative coronary angiography and compared these with Western estimates of coronary artery size. Material and Methods Between december 2003 and June 2004, 94 patients who underwent quantitative coronary angiography for evaluation of symptoms of ischemic heart disease and were found to have no coronary artery disease form the sample size. Results The dimensions of branches in the left coronary system in our patients were less and those of the distal circumflex, and the proximal and distal left anterior descending coronary arteries were significantly greater than those of Indian Asians living in the United Kingdom and the native Caucasians but the dimensions of the right coronary artery were significantly greater in our patients. Conclusions Coronary artery dimensions for at least some branches of the left coronary system are similar to that reported in the West and the dimensions of the right coronary are greater. These findings contradict the general perception that Indians have smaller coronary arteries.     

Alterations of the tumor suppressor gene ARLTS1 in ovarian cancer

ARLTS1 is a tumor suppressor gene initially described as a low-penetrance cancer gene: a truncated Trp149Stop (MUT) polymorphism is associated with general familial cancer aggregation and, particularly, high-risk familial breast cancer. DNA hypermethylation has been identified as a mechanism of ARLTS1 expression down-regulation in lung carcinomas and B-cell chronic lymphocytic leukemia. We found that, in the majority of ovarian carcinomas (61.5%) and in a significant proportion of ovarian and breast cancer cell lines (45%), ARLTS1 is strongly down-regulated due to DNA methylation in its promoter region. After ARLTS1 restoration by adenoviral transduction, only the negative TOV-112 and the homozygously mutated (MUT) MCF7 cells, but not the OV-90 cells expressing a normal ARLTS1 product, underwent apoptosis and inhibition of cell growth. Furthermore, ARLTS1 reexpression significantly reduced the tumorigenic potential of TOV-112 in nude mice. On the contrary, the ARLTS1-MUT induced significantly lower levels of apoptosis in infected cells and reduced in vivo tumorigenesis only partially, supporting the hypothesis that Trp149Stop polymorphism is retained in the general population and predisposes to cancer because of a reduction, but not full loss, of normal ARLTS1 function.