Atrophy of the residual alveolar ridge following tooth loss in an historical population

Oral Diseases (2010) 17 , 33–44 Objectives: To study the natural aetiopathology of jaw atrophy after tooth loss, unaltered by prosthetic procedures, an historical population without modern dental treatment was examined. Methods: Based on the hypothesis that there are predictable changes in shape during jaw‐atrophy, frequency and degree of atrophy as well as clinical aspects of bone quality and resorption were determined in the skeletal remains of 263 individuals. The potential association between age and frequency/severity of atrophy was analysed. Results: Atrophy in at least one jaw segment was present in 45.2% of the analysed jaw specimens. The residual ridge underwent a series of changes in shape and height following the pattern of resorption described for modern populations. The severity of these alterations was associated with the age of the individual and the region within the jaw. Atrophy was frequently related to structural degradation of the covering cortical layer. Conclusions: These findings prove that atrophy of the jaw evidently does occur, displaying similar patterns of resorption in a population without modern prosthetics, where the negative effect of ill‐fitting dentures is excluded. The basic information about alterations of shape and the cortical layer covering the residual crest might help to provide a deeper insight into aetiopathological mechanisms of this common oral disease.     

Marginal ulceration after laparoscopic gastric bypass: an analysis of predisposing factors in 260 patients

Background Marginal ulceration after Roux-en-Y gastric bypass (RYGB) is diagnosed in 1% to 16% of patients. The factors predisposing patients to marginal ulceration are still unclear. Methods A total of 260 patients who underwent laparoscopic RYGB were retrospectively reviewed. Data regarding demographics, comorbidities, body mass index (BMI), Helicobacter pylori infection, gastrojejunal (GJ) anastomotic leaks, postoperative bleeding, operative time, type of suture material, and marginal ulcer formation were collected. Fisher’s exact test was used for statistical analysis of discrete variables, and Student’s t-test was used for continuous variables. Statistical significance was set at an alpha of 0.05. Results The overall marginal ulceration rate was 7%. Demographic data (age, gender distribution, BMI) did not differ significantly between patients who experienced marginal ulceration and those who did not (p > 0.05). Similarly, technical factors (choice of permanent or absorbable suture for the GJ anastomosis, attending as primary surgeon, robotic GJ, operative time, postoperative hematocrit drop) were not statistically different between the two groups (p > 0.05). Finally, the prevalence of comorbidities (diabetes, hypertension, obstructive sleep apnea, musculoskeletal complaints, dyslipidemia, gastroesophageal reflux disease [GERD] and peptic ulcer disease [PUD]) did not differ significantly between the two groups (p > 0.05). However, preoperative H. pylori infection, although adequately treated, was twice as common among the patients who had marginal ulceration (32%) as among those who did not (12%) (p = 0.02). All the patients who experienced marginal ulcers had complete resolution of symptoms with proton pump inhibitors and sucralfate. No reoperations were required for marginal ulceration. Conclusion Helicobacter pylori may potentiate marginal ulcer formation. The authors hypothesize that H. pylori damages the mucosal barrier in a way that persists postoperatively, which may precipitate marginal ulceration even when the organism has been medically eradicated. Submitted for oral/poster presentation at the annual meeting of the Society of American Gastrointestinal Endoscopic Surgeons (SAGES), April 2007     

The release of systemic inflammatory mediators is independent of cardiopulmonary bypass temperature

OBJECTIVE: The aim of this study was to investigate the effect of systemic CPB temperature on the production of the key mediators of the systemic inflammatory response to coronary artery bypass graft (CABG) surgery. DESIGN: Randomized clinical study. SETTING: University hospital. PARTICIPANTS: Thirty patients undergoing first-time CABG surgery. INTERVENTIONS: The patients were randomized to hypothermic (32 degrees C, n = 15) or normothermic (36 degrees C, n = 15) CPB. MEASUREMENTS AND MAIN RESULTS: Plasma interleukin (IL)-6, IL-8, IL-10, C-reactive protein (CRP), cortisol, and neutrophils were measured the day before operation, at closure of the sternum, and 4, 16, and 44 hours later. The cytokine, CRP, cortisol, and neutrophil responses were independent of temperature during CPB with peak concentrations of IL-10 at closure of the sternum followed by IL-6, IL-8, cortisol, neutrophils, and finally CRP. A correlation between maximal plasma concentrations of IL-10 and cortisol was seen in both groups after surgery (p = 0.02). Drainage after surgery was lower after normothermic CPB (p=0.02), with no difference in the requirement for blood transfusion. All patients were discharged from the intensive care unit within 24 hours after surgery. CONCLUSIONS: The release of systemic inflammatory mediators after cardiac surgery was independent of mild hypothermia (32 degrees C) versus normothermia (36 degrees C) during CPB.     

Ancient DNA reveals late survival of mammoth and horse in interior Alaska

Causes of late Quaternary extinctions of large mammals (“megafauna”) continue to be debated, especially for continental losses, because spatial and temporal patterns of extinction are poorly known. Accurate latest appearance dates (LADs) for such taxa are critical for interpreting the process of extinction. The extinction of woolly mammoth and horse in northwestern North America is currently placed at 15,000–13,000 calendar years before present (yr BP), based on LADs from dating surveys of macrofossils (bones and teeth). Advantages of using macrofossils to estimate when a species became extinct are offset, however, by the improbability of finding and dating the remains of the last-surviving members of populations that were restricted in numbers or confined to refugia. Here we report an alternative approach to detect ‘ghost ranges’ of dwindling populations, based on recovery of ancient DNA from perennially frozen and securely dated sediments (sedaDNA). In such contexts, sedaDNA can reveal the molecular presence of species that appear absent in the macrofossil record. We show that woolly mammoth and horse persisted in interior Alaska until at least 10,500 yr BP, several thousands of years later than indicated from macrofossil surveys. These results contradict claims that Holocene survival of mammoths in Beringia was restricted to ecologically isolated high-latitude islands. More importantly, our finding that mammoth and horse overlapped with humans for several millennia in the region where people initially entered the Americas challenges theories that megafaunal extinction occurred within centuries of human arrival or were due to an extraterrestrial impact in the late Pleistocene.