Influence on binding of third-order torque to second-order angulation

Using an earlier model, which described the critical contact angle for binding from second-order angulation alone, a more generalized model is derived that combines the effects of angulation and torque. From this vantage point, the onset of binding is evaluated for 3 scenarios: second-order angulation alone, third-order torque only, and a combination of second-order angulation and third-order torque. These scenarios are detailed by plotting the critical contact angle for binding against the torque angle as a function of 10 wire dimensions (16 x 16, 16 x 22, 17 x 17, 17 x 22, 17 x 25, 18 x 18, 18 x 22, 18 x 25, 19 x 25, and 21 x 25 mil), 4 bracket widths (70, 100, 130, and 160 mil), and 4 bracket slots (18, 20.5, 22, and 24.5 mil). From these plots, we learn that each wire base dimension (eg, an 18-mil base as found in 18 x 18-mil, 18 x 22-mil and 18 x 25-mil archwires) has a common maximum critical contact angle for binding. Moreover, each wire-slot combination has a common maximum torque angle, which is independent of bracket width. Finally, we learn that archwire-bracket combinations that use a metric 0.5-mm slot might have some advantages with regard to torquing--given the current philosophy that light, continuous forces are more favorable.     

Early outcomes of surgery for small bowel obstruction: analysis of risk factors

OBJECTIVES: The study aimed to review the etiologies of patients who underwent surgery for small bowel obstruction (SBO) and to evaluate the risk factors affecting the early postoperative outcomes. MATERIALS AND METHODS: A case series of 430 patients (252 men) with a mean age of 64.5 years, who underwent 437 operations for SBO, were retrospectively reviewed. RESULTS: Peritoneal adhesions and hernia were the most common causes of SBO, contributing 42.3 and 26.8% of all cases, respectively. Strangulation occurred in 27.7% and caused nonviable bowel in 13.0% of obstructing episodes. Old age (age >/= 70 years), female patient, nonadhesive obstruction, and hernia were the independent significant factors associated with bowel strangulation. The 30-day mortality was 6.5%, and the median postoperative hospital stay was 8 days. Old age, the presence of premorbid pulmonary disease, and malignant obstruction were the independent factors associated with operative mortality. The overall complication rate was 35.5%, and old age was the only significant factor associated with postoperative complications. CONCLUSIONS: Surgery for SBO is still associated with significant mortality and morbidity. As old age is significantly associated with an increased incidence of strangulation, operative mortality, and complications, this group of patients should be managed with extra cautions to avoid unfavorable outcome of surgery.     

Myasthenia Gravis Appearing After Thymectomy: a Case Report and Review of the Literature

A small proportion of thymoma patients without myasthenia gravis (MG) have been observed to develop MG after total removal of the thymoma. However, the underlying cause is not yet known due to the rarity of postoperative MG patients. We report a 39-year-old man in whom MG appeared after surgical removal of a thymoma. Computed tomography and magnetic resonance imaging showed no signs of recurrent or metastatic thymoma. Administration of pyridostigmine bromide resulted in the prompt improvement of myasthenic symptoms. Our observations indicate that postoperative follow-up care with monitoring of possible postoperative MG is necessary after resecting a thymoma.     

Stromal progenitor cell therapy corrects the wound-healing defect in the ischemic rabbit ear model of chronic wound repair

Chronic wounds create a formidable clinical problem resulting in considerable morbidity and healthcare expenditure. The etiology for wound healing impairment appears to be multifactorial; however, ischemia is a common factor in most types of chronic wounds. Ideal therapy for such wounds would be to correct deficiencies in growth factors and matrix components and provide cellular precursors required for timely wound closure. We hypothesized that stromal progenitor cell (SPC) therapy could correct the ischemic wound-healing defect through both direct and indirect mechanisms. To test this hypothesis, we used the ischemic rabbit ear model of chronic wound healing. We found that treatment of the wounds with SPCs was able to reverse the ischemic wound-healing impairment, with improved granulation tissue formation and reepithelialization compared with vehicle or bone marrow mononuclear cell controls. In vitro, SPCs were found to produce factors involved in angiogenesis and reepithelialization, and extracellular matrix components, providing evidence for both direct and indirect mechanisms for the observed correction of the healing impairment in these wounds. Treatment of ischemic wounds with SPCs can dramatically improve wound healing and provides a rationale for further studies focused on SPCs as a potential cellular therapy in impaired wound healing.