Home About us Contact
|
Home About us Contact | ||
|
|
||
P=
Selected AbstractsMonocytes and T lymphocytes contribute to a predominance of interleukin 6 and interleukin 10 in systemic lupus erythematosus,CYTOMETRY, Issue 4 2009Susana Mellor-Pita Abstract Objective To investigate the contribution of T lymphocytes and monocytes to cytokine production in systemic lupus erythematosus (SLE). Methods Forty-five SLE patients and 19 healthy volunteers were included. Serum levels of tumor necrosis factor alpha (TNF,), interferon gamma (IFN,), interleukin (IL)-6, and IL10 were quantified by ELISA. The cytokine production capacities of peripheral blood mononuclear cells were assessed by culturing in vitro with PMA+Ionomycin or LPS. The intracellular cytokine expression was measured by flow cytometry in T lymphocytes and monocytes, respectively. The influence of the disease activity (measured as the SLE-disease activity index; SLEDAI) and the treatment the patients were receiving was evaluated. Results Serum IL10, IL6, and TNF, levels were increased in patients (P , 0.01), and a higher spontaneous (without stimuli) intracellular expression of IL10 in CD4+ and CD8+ T lymphocytes (P < 0.05) and of IL6 in monocytes (P = 0.01) were found. After stimulation, patients presented a higher percentage of CD4+ and CD8+ T lymphocytes producing IL4 and IL10 (P , 0.01), and of monocytes producing IL6 (P = 0.04) and IL10 (P = 0.008). The SLEDAI score was positively correlated with the percentage of CD4+IL10+ and CD8+IL10+ T lymphocytes (P < 0.01), and inversely correlated with CD8+TNF,+ (P= 0.02), CD4+IFN,+ (P = 0.04) and CD8+ IFN,+ (P = 0.002) T lymphocytes. Patients receiving high dose prednisone produced higher IL10, but they also were the patients with a more active disease. Conclusion Monocytes and T lymphocytes (CD4+ and CD8+) contribute to an overproduction of IL6 and IL10 in SLE; this correlates with the disease activity but is independent of the treatment the patients are receiving. © 2009 Clinical Cytometry Society [source] A comparison of risk factors for habitual violence in pre-trial subjectsACTA PSYCHIATRICA SCANDINAVICA, Issue 2002S. Z. Kaliski Objective: Pre-trial referrals to the Valkenberg Hospital forensic unit over a 6-month period were studied. Habitually violent offenders were compared with those with no history of violence. Methods:, Risk factors known to be associated with violent behaviour were elicited, i.e. demographics, behaviour during index offence (such as impulsivity, identity of victim, use of weapon, accomplices, intoxication, psychotic symptoms), psychiatric and family histories, history of suicide attempts, past child abuse, head injury, criminal record, psychiatric diagnosis and presence of medical disorders. EEG's, Barratt's Impulsivity, Zuckerman's Sensation Seeking and Mini-Mental Scales were administered. Behaviour in the ward during the 30 days was also appraised. Logistic regression models were used to determine relative risks. Results:, There were 155 subjects; 89.7% were male, 71.6% were single and 58.7% were unemployed. For 44.5% the index offence was violent, and 9.7% had committed sexual offences; 61.9% had histories of habitual violence. A psychotic disorder was diagnosed in 32.3% and a personality disorder in 48.4%. Habitually violent subjects were distin- guished by a history of issuing threats (OR=3.68; CI=3.19,4.16; P= 0.000), delusions of persecution (OR=3.43; CI=2.67,4.17; P=0.001), history of conduct disorder (OR=1.95; CI=1.70,2.19; P=0.006), alcohol/substance abuse (OR=2.08; CI=1.53,2.61; P=0.008) and violent index offence (OR=1.66; CI=1.54,2.61; P=0.035). Conclusion: This seems to confirm the relationship between threats, feeling threatened, psychosis, a history of antisocial behaviour and alcohol abuse. [source] Extreme altitude mountaineering and Type 1 diabetes; the Diabetes Federation of Ireland Kilimanjaro ExpeditionDIABETIC MEDICINE, Issue 9 2001K. Moore Abstract Aims To examine the effects of extreme altitude mountaineering on glycaemic control in Type 1 diabetes, and to establish whether diabetes predisposes to acute mountain sickness (AMS). Methods Fifteen people with Type 1 diabetes and 22 nondiabetic controls were studied during the Diabetes Federation of Ireland Expedition to Kilimanjaro. Daily insulin requirements, blood glucose estimations and hypoglycaemic attacks were recorded in diaries by the people with diabetes. The performance of blood glucose meters at altitude was assessed using standard glucose solutions. Symptoms of acute mountain sickness were recorded daily by people with diabetes and by the nondiabetic controls using the Lake Louise Scoring Charts. The expedition medical team recorded the incidence of complications of altitude and of diabetes. The final height attained for each individual was recorded by the expedition medical team and verified by the expedition guides. Results The final altitude ascended was lower in the diabetic than the nondiabetic group (5187 ± 514 vs. 5654 ± 307 m, P= 0.001). The mean daily insulin dose was reduced from 67.1 ± 28.3,32.9 ± 11.8 units (P < 0.001), but only 50% of recorded blood glucose readings were within the target range of 6,14 mmol/L. There were few hypoglycaemic attacks after the first two days of climbing. Both blood glucose meters tested showed readings as low as 60% of standard glucose concentrations at high altitude and low temperatures. The Lake Louise questionnaires showed that symptoms of AMS occurred equally in the diabetic and nondiabetic groups. There were two episodes of mild diabetic ketoacidosis; two of the diabetic group and three of the nondiabetic group developed retinal haemorrhages. Conclusions People with Type 1 diabetes can participate in extreme altitude mountaineering. However, there are significant risks associated with this activity, including hypoglycaemia, ketoacidosis and retinal haemorrhage, with the additional difficulties in assessing glycaemic control due to meter inaccuracy at high altitude. People with Type 1 diabetes must be carefully counselled before attempting extreme altitude mountaineering. Diabet. Med. 18, 749,755 (2001) [source] Detection of tumor cells in body cavity fluids by flow cytometric and immunocytochemical analysisDIAGNOSTIC CYTOPATHOLOGY, Issue 8 2006Awtar Krishan Ph.D. Abstract Measurement of electronic volume versus DNA content of nuclei can be used to discriminate between normal and malignant cells. Epithelial membrane antigen immunocytochemistry (EMA-ICC), a helpful ancillary test in body cavity fluids, is not universally accurate for detecting malignancy in effusions. The current study was undertaken to determine if multiparametric flow cytometry (based on simultaneous analysis of light scatter, nuclear volume, DNA, and nuclear protein content) in combination with (EMA-ICC) could be used for the detection of malignant cells in peritoneal and pleural fluids. We studied 130 body cavity fluids (68 peritoneal and 62 pleural fluids) by conventional cytology and multiparametric laser flow cytometry. EMA-ICC was performed using EMA antibodies and L-SAB detection system (DakoCytomation, Carpinteria, CA). EMA-ICC had significantly higher sensitivity than conventional cytology (79% versus 59%, P = 0.016) and ploidy (79% versus 38%, P = 0.001). Cytology had significantly higher specificity than ploidy (97% versus 82%, P = 0.012). The differences in specificity between EMA-ICC and ploidy (87% versus 82%, P= 0.607) or EMA-ICC and cytology (87% versus 97%, P = 0.109) were not statistically significant. However, assuming serial testing, sensitivity increased significantly for the combinations of cytology and EMA-ICC (79.4%, P = 0.016) and cytology and ploidy (73.5%, P = 0.004) as compared to cytology alone (58.8%). Also, the combination of cytology and ploidy had a higher sensitivity than ploidy alone (73% versus 38%, P < 0.0001). However, the sensitivity associated with the three tests used in serial (85.3%) was not significantly different from the sensitivities corresponding to the combination of cytology and EMA-ICC (79%) or cytology and ploidy (73%). Multiparametric flow cytometry utilizing high resolution DNA, nuclear volume, protein measurement, and ICC, in combination with cytomorphology, may be a valuable tool for rapid identification of malignant cells in body cavity fluids. Diagn. Cytopathol. 2006;34:528,541. © 2006 Wiley-Liss, Inc. [source] Associations of risk factors obesity and occupational airborne exposures with CDKN2A/p16 aberrant DNA methylation in esophageal cancer patientsDISEASES OF THE ESOPHAGUS, Issue 7 2010S. Mohammad Ganji SUMMARY It is known that obesity and occupational airborne exposure such as dust are among risk factors of esophageal cancer development, in particular squamous cell carcinoma (SCC) of esophagus. Here, we tested whether these factors could also affect aberrant DNA methylation. DNAs from 44 fresh tumor tissues and 19 non-tumor adjacent normal tissues, obtained from 44 patients affected by SCC of esophagus (SCCE), were studied for methylation at the CDKN2A/p16 gene promoter by methylation-specific polymerase chain reaction assay. Statistical methods were used to assess association of promoter methylation with biopathological, clinical, and personal information data, including obesity and airborne exposures. Methylation at the CDKN2A/p16 gene promoter was detected in 12 out of 44 tumor samples. None of the non-tumor tissues exhibited the aberrant methylation. Our results confirmed previously described significant association with low tumor stage (P= 0.002); in addition, we found that obesity (P= 0.001) and occupational exposure (P= 0.008) were both significantly associated with CDKN2A/p16 promoter methylation. This study provides evidence that obesity and occupational exposure increase the risk of developing esophageal cancer through an enhancement of CDKN2A/p16 promoter methylation. [source] The role and frequency of glutathione s-transferase P1 polymorphism in Iranian patients affected with reflux esophagitisDISEASES OF THE ESOPHAGUS, Issue 7 2010N. Zendehdel SUMMARY Reflux esophagitis is a common complication of the gastroesophageal reflux disease. Glutathione s-transferases (GSTs) have important role in the protection of cells from the products of oxidative stress. GSTP1*B allele has a correlation with susceptibility to several diseases. In this case-control study, the role and frequency of GSTP1 polymorphism was evaluated in Iranian patients with erosive reflux esophagitis. Seventy patients with erosive reflux esophagitis and 75 normal individuals were enrolled in this study. The grade of esophagitis was determined via endoscopy. DNA was extracted from venous blood of each subject using the salting out method. GSTP1 genetic polymorphisms were detected using the polymerase chain reaction restriction fragment length polymorphism method. There was a significant difference in GSTP1 genotype frequency between patients and normal groups (P= 0.006). Also, in the patient group, the grade B of esophagitis was significantly associated with variant GSTP1 genotype (P= 0.028). The rate of throat pain symptom was higher in the no-variant group (P < 0.036). The GSTP1*B allele frequency in Iranian normal groups is similar to Orientals. Reflux esophagitis are more commonly found in variant (*B/*B and *A/*B) GSTP1 genotypes. In addition, GSTP1 polymorphism is correlated with a higher grade of esophagitis. [source] Original article: Quality of life after esophagectomy and endoscopic therapy for Barrett's esophagus with dysplasiaDISEASES OF THE ESOPHAGUS, Issue 6 2010D. Schembre SUMMARY Esophagectomy (EG) and endoscopic therapy (ET) can eradicate Barrett's esophagus with early neoplasia. Their relative effect on quality of life is unknown. The 36-item Short Form Health Survey (SF-36) and Gastrointestinal Quality of Life Index (GIQLI) questionnaires were sent to all patients who underwent either EG or ET at our institution over the last 9 years. Groups were stratified by age and American Society of Anesthesia (ASA) class. Surveys were sent to 77 patients and completed by 14 EG (50%) and by 28 ET patients (57%). The average time between treatment and survey was 4 years in the ET group and 5 years in the EG group. There were no significant differences in SF-36 scores between EG and ET patients except for superior physical functioning among EG patients 65 and older QOL scores among EG and ET groups were not significantly different than sex age-matched controls. GIQLI scores were similar between ET and EG patients of all ages (P= 0.60). GIQLI scores were higher among younger ET patients than young EG patients (P= 0.049). GIQLI scores also tended to be higher among ASA 1 and 2 ET patients than ASA 1 and 2 EG patients, but this did not reach statistical significance (P= 0.09). EG and ET for early Barrett's neoplasia appear to have similar impact on QOL 1 year or more after treatment compared with age-matched controls. Negative QOL impact appears to be greater for younger patients undergoing EG than for ET. [source] Effect of pantoprazole in patients with chronic laryngitis and pharyngitis related to gastroesophageal reflux disease: clinical, proximal, and distal pH monitoring resultsDISEASES OF THE ESOPHAGUS, Issue 4 2010S. Karoui SUMMARY Few studies had evaluated the results of proton pump inhibitors on distal and proximal pH recording using a dual-channel probe. The aim of this study was to determine the clinical and pH-metric effect of treatment with pantoprazole 80 mg for 8 weeks in patients with ear, nose, and throat (ENT) manifestations of gastroesophageal reflux disease associated with pathological proximal acid exposure. We conducted a prospective open study. Patients included had to have chronic pharyngitis or laryngitis, and a pathological gastroesophagopharyngeal reflux. All patients received treatment with pantoprazole 80 mg daily for 8 weeks. One week after the end treatment, patients had a second ENT examination and a 24-hour pH monitoring using dual-channel probe. We included 33 patients (11 men, 22 women). A pathological distal acid reflux was found in 30 patients (91%). After treatment, the improvement of ENT symptoms was found in 51.5% of patients. Normalization of 24-hour proximal esophageal pH monitoring was observed in 22 patients (66%). After treatment, the overall distal acid exposure, the number of distal reflux events, and the number of reflux during more than 5 minutes were significantly decreased (respectively: 19.4% vs 7.2% [P < 0.0001], 62.7 vs 28.4 [P < 0.0001], and 10.4 vs 3.9 [P < 0.0001] ). Similarly, in proximal level, the same parameters were significantly decreased after treatment (respectively: 6.8% vs 1.6% [P < 0.0001], 32.6 vs 8.1 [P < 0.0001], and 3.4 vs 0.6 [P= 0.005] ). Treatment with pantoprazole reduced the frequency and severity of gastroesophagopharyngeal acid reflux in patients with chronic pharyngitis and laryngitis. [source] Combined treatment of achalasia , botulinum toxin injection followed by pneumatic dilatation: long-term resultsDISEASES OF THE ESOPHAGUS, Issue 2 2010R. Kroupa SUMMARY Injection of botulinum toxin (BT) and pneumatic dilatation are available methods in nonsurgical treatment of achalasia. Authors anticipate beneficial effect of prior BT injection on the success of pneumatic dilatation and duration of its effect. There are no long-term data available to assess efficacy of combined treatment. From 1998 to 2007, 51 consecutive patients (20 men and 31 women, age 24,83) with achalasia were included and prospectively followed up. Each patient received injection of 200 IU of BT into the lower esophageal sphincter (LES) during endoscopy and 8 days later pneumatic dilatation (PD) under X-ray control was performed. The follow-up was established every 3 months first year and then annually. The efficacy was evaluated by a questionnaire concerning patient's symptoms and manometry. Results were compared with 40 historical controls (16 men and 24 women, age 26,80) treated by PD alone using the same method and follow-up. Fifty-one patients underwent combined treatment. Four patients failed in follow-up and were not included for analysis. The mean duration of follow-up was 48 months with range 12,96 months. Thirty-four of forty-seven (72%) patients were satisfied with results with none or very rare and mild troubles at the time of the last visit. Forty-one patients were followed up more than 2 years. Effect of therapy lasted in 75% (31/41) of them. In 17 patients, more than 5 years after treatment, effect lasted in 12 (70%). Mean tonus of LES before therapy was 29 mm Hg (10,80), 3 months after therapy decreased to 14 mmHg (5,26). The cumulative 5 years remission rate (±95% CI) in combined treated patients 69% ± 8% was higher than in controls 50% ± 9%; however it, was not statistically significant (P= 0.07). In control group 1, case of perforation (2.5%) occurred. Eight patients (17%) with relapse of dysphagia were referred to laparoscopic Heller myotomy with no surgical complication. The main adverse effect was heartburn that appeared in 17 patients (36%). Initial injection of BT followed by PD seems to be effective for long-term results with fewer complications. But the combined therapy is not significantly superior to PD alone. [source] Is esophagoscopy necessary for corrosive ingestion in adults?DISEASES OF THE ESOPHAGUS, Issue 8 2009Burcin Celik SUMMARY The aim of the study was to determine whether early esophagoscopy is really necessary for the patients who have ingested a corrosive agent. Patients who were followed up with the diagnosis of corrosive ingestion in our clinic between the years 1998 and 2008 were studied retrospectively. The data were collected through the medical records of the patients and from interviews with them. The analyzed parameters included age, gender, the nature and the amount of the ingested agent, whether the event was accidental or suicidal, diagnostic tools, treatment and the results of the treatment, and long-term follow up. Over a 10-year period, a total of 124 cases of corrosive ingestion cases were determined. Of these, 64 (51.6%) were male and 60 (48.4%) were female. The mean age was 38 ± 17.5 years. The most commonly ingested corrosive agents were sodium hypochlorite in 50 (40.3%) patients and hydrochloric acid in 33 (26.6%) patients. The mean admission time for the emergency department after ingestion of the corrosive agent was 2.5 ± 3.7 hours. Ingestion was accidental in 82% of the patients and as a result of a suicide attempt in 18%. The amount of ingested corrosive agent in the suicidal group (190 ± 208.3 mL) was higher than that of accidental group (66 ± 58.3 mL) (P= 0.012). Nine patients underwent esophagoscopy, six of which were performed in other clinical centers. Only three (2.4%) patients experienced esophageal stricture, which were treated with repeated dilatations. In the long-term follow up, we could get in touch with only 63 patients and none of them had complications due to corrosive ingestion. The follow-up period ranged from 1 to 120 months (median 45 ± 29.2 months). Based on our study, early esophagoscopy appears to be unnecessary in adult patients who ingested the corrosive agent accidentally. A larger prospective study is needed to answer the question. [source] Medium-term outcome of fundoplication after lung transplantationDISEASES OF THE ESOPHAGUS, Issue 8 2009P. R. Burton SUMMARY Gastroesophageal reflux disease (GERD) in lung transplant recipients has gained increasing attention as a factor in allograft failure. There are few data on the impact of fundoplication on survival or lung function, and less on its effect on symptoms or quality of life. Patients undergoing fundoplication following lung transplantation from 1999 to 2005 were included in the study. Patient satisfaction, changes in GERD symptoms, and the presence of known side effects were assessed. The effect on lung function, body mass index, and rate of progression to the bronchiolitis obliterans syndrome (BOS) were recorded. Twenty-one patients (13 males), in whom reflux was confirmed on objective criteria, were included, with a mean age of 43 years (range 20,68). Time between transplantation and fundoplication was 768 days (range 145,1524). The indication for fundoplication was suspected microaspiration in 13 and symptoms of GERD in 8. There was one perioperative death, at day 17. There were three other late deaths. Fundoplication did not appear to affect progression to BOS stage 1, although it may have slowed progression to stage 2 and 3. Forced expiratory volume-1% predicted was 72.9 (20.9), 6 months prior to fundoplication and 70.4 (26.8), six months post-fundoplication, P= 0.33. Body mass index decreased significantly in the 6 months following fundoplication (23 kg/m2 vs. 21 kg/m2, P= 0.05). Patients were satisfied with the outcome of the fundoplication (mean satisfaction score 8.8 out of 10). Prevalence of GERD symptoms decreased significantly following surgery (11 of 14 vs. 4 of 17, P= 0.002). Fundoplication does not reverse any decline in lung function when performed at a late stage post-lung transplantation in patients with objectively confirmed GERD. It may, however, slow progression to the more advanced stages of BOS. Reflux symptoms are well controlled and patients are highly satisfied. Whether performing fundoplication early post-lung transplant in selected patients can prevent BOS and improve long-term outcomes requires formal evaluation. [source] Prognostic factors of radiotherapy in patients with node-positive thoracic esophageal squamous cell carcinoma after radical surgeryDISEASES OF THE ESOPHAGUS, Issue 6 2009Jin-Cheng Lu SUMMARY The aim of this study was to retrospectively analyze and assess the outcomes and prognostic factors of radiotherapy in patients with node-positive thoracic esophageal squamous cell carcinoma after radical surgery. One hundred twenty-six patients with node-positive thoracic esophageal squamous cell carcinoma who had undergone adjuvant therapy (postoperative radiotherapy alone or postoperative sequential chemoradiotherapy without receiving postoperative concurrent chemoradiotherapy) after radical surgery, were retrospectively reviewed from January 1996 to December 2003. Univariate and multivariate analyses were performed using log-rank and Cox proportional hazard models, and survival curves were estimated using the Kaplan-Meier method. The 1-, 3- and 5-year overall survival rates of all 126 patients were 71.4, 39.1, and 22.0%, and disease-free survival rates were 64.3, 36.4, and 21.5%, respectively. Lymph node ratio (the ratio of the number of metastatic lymph nodes to the number of lymph nodes removed, LNR) ,0.2 (P= 0.006), pT3 + pT4 (P= 0.06) and sequential chemoradiotherapy (P= 0.08) were associated with a poorer survival by univariate analysis. In multivariate analysis, LNR (P= 0.01, hazard ratio = 0.57, 95% confidence interval, 0.37,0.87) and tumor depth of invasion (P= 0.03, hazard ratio = 0.62, 95% confidence interval, 0.41,0.96) were the independent predictors of survival. Sequential chemoradiotherapy receded survival tendency without significant difference (P= 0.09, hazard ratio = 0.64, 95% confidence interval, 0.37,1.08). Therefore, LNR and tumor depth of invasion were the independent prognostic factors of radiotherapy in patients with node-positive thoracic esophageal squamous cell carcinoma after radical surgery. The addition of chemotherapy does not seem to confer a survival benefit. [source] An increased proportion of inflammatory cells express tumor necrosis factor alpha in idiopathic achalasia of the esophagusDISEASES OF THE ESOPHAGUS, Issue 5 2009A. Kilic SUMMARY Achalasia is a motility disorder characterized by the absence of coordinated peristalsis and incomplete relaxation of the lower esophageal sphincter. The etiology remains unclear although dense inflammatory infiltrates within the myenteric plexus have been described. The nature of these infiltrating cells is unknown. The aim of this study was to evaluate the expression of proinflammatory cytokines , namely, tumor necrosis factor alpha and interleukin-2 , in the distal esophageal muscle in patients with achalasia. Lower esophageal sphincter muscle from eight patients undergoing myotomy or esophagectomy for achalasia of the esophagus were obtained at the time of surgery. Control specimens consisted of similar muscle taken from eight patients undergoing operation for cancer or Barrett's esophagus. The expression of tumor necrosis factor alpha and interleukin-2 were assessed by immunohistochemistry. The total number of inflammatory cells within the myenteric plexus were counted in five high power fields. The percentage of infiltrating cells expressing tumor necrosis factor alpha or interleukin-2 was calculated. Clinical data including demographics, preoperative lower esophageal sphincter pressure, duration of symptoms, and dysphagia score (1 = no dysphagia to 5 = dysphagia to saliva) were obtained through electronic medical records. Statistical comparisons between the groups were made using the unpaired t -test, Fisher's exact test, or Mann,Whitney U test, with a two-tailed P -value less than 0.05 being considered significant. The total number of inflammatory cells was found to be similar between the groups. A significantly higher proportion of inflammatory cells expressed tumor necrosis factor alpha in achalasia as compared with controls (22 vs. 11%; P= 0.02). A similar percentage of infiltrating cells expressed interleukin-2 (40 vs. 41%; P= 0.87). Age, gender, preoperative lower esophageal sphincter pressure, or dysphagia score were not correlated to expression of these cytokines. There was, however, a significant inverse correlation between duration of symptoms and the proportion of inflammatory cells expressing tumor necrosis factor alpha in achalasia (P= 0.007). In conclusion, a higher proportion of infiltrating inflammatory cells expressed tumor necrosis factor alpha in achalasia. Furthermore, this proportion appears to be highest early in the disease process. Further studies are required to more clearly delineate the role of tumor necrosis factor alpha in the pathogenesis of this idiopathic disease. [source] A study comparing tolerability, satisfaction and acceptance of three different techniques for esophageal endoscopy: sedated conventional, unsedated peroral ultra thin, and esophageal capsuleDISEASES OF THE ESOPHAGUS, Issue 5 2009G. Nakos SUMMARY Three methods of esophagoscopy are available until now: sedated conventional endoscopy, unsedated ultrathin endoscopy, and esophageal capsule endoscopy. The three methods carry comparable diagnostic accuracy and different complication rates. Although all of them have been found well accepted from patients, no comparative study comprising the three techniques has been published. The aim of this study was to compare the three methods of esophagoscopy regarding tolerability, satisfaction, and acceptance. Twenty patients with large esophageal varices and 10 with gastroesophageal reflux disease were prospectively included. All patients underwent consecutively sedated conventional endoscopy, unsedated ultrathin endoscopy, and esophageal capsule endoscopy. After each procedure, patients completed a seven-item questionnaire. The total positive attitude of patients toward all methods was high. However, statistical analysis revealed the following differences in favor of esophageal capsule endoscopy: (i) total positive attitude has been found higher (,2= 18.2, df = 2, P= 0.00), (ii) less patients felt pain (,2= 6.9, df = 2, P= 0.03) and discomfort (,2= 22.1, df = 2, P= 0.00), (iii) less patients experienced difficulty (,2= 13.7, df = 2, P= 0.01), and (iv) more patients were willing to undergo esophageal capsule endoscopy in the future (,2= 12.1, df = 2, P= 0.002). Esophageal capsule endoscopy was characterized by a more positive general attitude and caused less pain and discomfort. Sedated conventional endoscopy has been found more difficult. More patients would repeat esophageal capsule endoscopy in the future. Patients' total position for all three available techniques for esophageal endoscopy was excellent and renders the observed advantage of esophageal capsule endoscopy over both sedated conventional and unsedated ultrathin endoscopy a statistical finding without a real clinical benefit. [source] Association of erosive esophagitis with Helicobacter pylori eradication: a role of salivary bicarbonate and glycoprotein secretionDISEASES OF THE ESOPHAGUS, Issue 4 2009D. B. Namiot SUMMARY In some populations, Helicobacter pylori eradication is associated with development of erosive esophagitis. The aim of this study was to evaluate the contribution of salivary bicarbonate and glycoprotein secretion to the pathogenesis of erosive esophagitis developing after H. pylori eradication. Gastroscopy and saliva collection were performed at recruitment and 12 months after completion of eradication therapy. Eighty-eight patients with duodenal ulcer were recruited to the study. Erosive esophagitis was found in 13 patients (grade A, 8 patients; grade B, 4 patients; grade C, 1 patient). Among the 74 subjects who completed the study, erosive esophagitis was detected in 21 patients (grade A, 15 patients; grade B, 6 patients); they all were successfully eradicated. Bicarbonate and glycoprotein secretion was not found to differ significantly between the subjects with and without erosive esophagitis both before and 1 year after H. pylori eradication. However, it was lower in H. pylori -infected (baseline) than in H. pylori -noninfected erosive esophagitis subjects (1 year after successful eradication) (bicarbonate 2.34 [1.29,3.40)]vs. 3.64 [2.70,4.58]µmol/min and glycoprotein 0.23 [0.15,0.31]vs. 0.35 [0.28,0.43] mg/min, P= 0.04 and P= 0.04, respectively). We conclude that changes in salivary bicarbonate and glycoprotein secretion related to H. pylori eradication do not promote the development of erosive esophagitis in duodenal ulcer patients. [source] Evaluation of systemic oxidative status and mononuclear leukocytes DNA damage in children with caustic esophageal strictureDISEASES OF THE ESOPHAGUS, Issue 4 2006M. Kaya SUMMARY., Esophageal stricture (ES) due to accidentally caustic digestions is a common problem in children. Mucosal damage and repeated dilatations lead to chronic inflammation and finally ES. We investigated the oxidative status and DNA damage of children with ES. Five children with ES were compared with the same age- and sex-matched healthy subjects. Oxidative status of plasma was evaluated by measuring myeloperoxidase (MPO) activity, and total peroxide (TP) level. Anti-oxidative status of the plasma was evaluated by measuring catalase (CAT) activity, and total antioxidant response (TAR). We used the Single Cell Gel Electrophoresis (also called Comet Assay) to measure DNA strand break in peripheral blood mononuclear leukocytes. Mean MPO activity and TP levels in the ES group were significantly higher than the control group (0.83 ± 0.35, 0.09 ± 0.03 and 0.98 ± 0.38, 0.34 ± 0.20, P = 0.009 and P = 0.047 respectively). There was no significant difference in CAT activity and TAR levels between the two groups (P = 0.347). DNA damage in patients with ES was increased compared to control subjects (108.8 ± 51.2 and 57.6 ± 31.2 arbitrary units, respectively), but this difference was not significant statistically (P= 0.09). This study shows that systemic oxidative stress and alteration at the nuclear level occur in patients with ES, as a result of multiple dilatations and tissue injury. On the other hand, these results support that patients with ES may benefit from antioxidant treatment. [source] Assessment of Elastic Properties of the Descending Thoracic Aorta By Transesophageal Echocardiography with Acoustic Quantification in Patients with a StrokeECHOCARDIOGRAPHY, Issue 8 2000Seok-Min Kang M.D. Previous studies have described the use of transesophageal echocardiography (TEE) with acoustic quantification (AQ) in assessing aortic elastic properties. We hypothesized that patients with a prior history of stroke (ST) may have a higher risk of atherosclerotic change in great vessels compared to nonstroke subjects (NST) and thus have decreased elastic properties. We assessed the elastic properties of the descending thoracic aorta (DTA) by TEE in ST patients and compared them with data in NST patients. Subjects included 31 with ST without any evidence of emboli originating from the heart (age 51 ± 10 years, M: F = 20: 11) and 25 age-matched NST (M: F= 8: 17). Patients with significant valvular heart disease including aortic and mitral regurgitation, left ventricular dysfunction (ejection fraction < 55%), and congenital heart disease were excluded. Compliance (C), distensibility (D), and stiffness index (SI) were measured using AQ and M-mode measurement at a level of the left atrium. We scored atherosclerotic risk factors (ARF) such as a history of diabetes, hypertension, smoking, hypercholesterolemia, and the presence of atheroma of DTA. There was no evidence of atheroma of DTA in NST. There were no significant differences in heart rate and systolic and diastolic blood pressure between ST and NST patients. Fractional area change (FAC) of DTA was significantly lower in ST than in NST patients (3.2 ± 1.6 vs 5.4 ± 2.5%, P= 0.000). ST patients had significantly lower C (1.2 ± 0.4 vs 1.5 ± 0.7 times 10 -3 cm2 mmHg -1, P= 0.039), lower D (0.8 ± 0.3 vs 1.5 ± 0.8 times 10 -3 mmHg -1, P= 0.000), and higher SI (10.3 ± 8.8 vs 5.3 ± 2.9, P= 0.006) than NST patients. ST patients without atheroma of DTA (n± 21) also had significantly lower C (1.1 ± 0.4 vs 1.5 ±0.7 times 10 -3 cm -2 mmHg -1, P= 0.038) and lower D (3.5 ± 1.4 vs 4.8 ± 2.4 times 10 -3 mmHg -1, P= 0.021) than NST patients. There was a significant positive correlation between SI and the score of ARF (r= 0.51, P= 0.000). The regional elastic properties of DTA measured by TEE with AQ and M-mode method were abnormal in ST. Therefore, TEE with AQ technique may have a possible clinical application for the detection of early atherosclerotic changes such as alteration of elastic properties in morphological normal DTA. [source] Effect of Inotropic Stimulation on Left Atrial Appendage Function in Atrial Myopathy of Chronic Atrial FibrillationECHOCARDIOGRAPHY, Issue 4 2000MASOOR KAMALESH M.D. Atrial fibrillation (AF) leads to remodeling of the left atrium (LA) and left atrial appendage (LAA), resulting in atrial myopathy. Reduced LA and LAA function in chronic AF leads to thrombus formation and spontaneous echo contrast (SEC). The effect of inotropic stimulation on LAA function in patients with chronic AF is unknown. LAA emptying velocity (LAAEV) and maximal LAA area at baseline and after dobutamine were measured by transesophageal echocardiography in 14 subjects in normal sinus rhythm (NSR) and 6 subjects in AF. SEC in the LA was assessed before and after dobutamine. LAAEV increased significantly in both groups. However, the LAAEV at peak dobutamine in patients with AF remained significantly lower than the baseline LAAEV in patients who were in NSR (P= 0.009). Maximal LAA area decreased significantly with dobutamine in both groups, but LAA area at peak dose of dobutamine inpatients with AF remained greater than baseline area in those in NSR (P= 0.01). Despite the increase in LAAEV, SEC improved in only two of five patients. We conclude that during AF, the LAA responds to inotropic stimulation with only a modest improvement in function. [source] Echocardiographic Doppler Evaluation of Left Ventricular Diastolic Filling in Older, Highly Trained Male Endurance AthletesECHOCARDIOGRAPHY, Issue 1 2000PETER R. JUNGBLUT M.D. Previously published data have suggested that endurance training does not retard the normative aging impairment of early left ventricular diastolic filling (LVDF). Those studies, suggesting no effect of exercise training, have not examined highly trained endurance athletes or their LVDF responses after exercise. We therefore compared LVDF characteristics in a group of older highly trained endurance athletes (n= 12, mean age 69 years, range 65,75) and a group of sedentary control subjects (n= 12, mean age 69 years, range 65,73) with no cardiovascular disease. For all subjects, M-mode and Doppler echocardiographic data were obtained at rest. After baseline studies, subjects underwent graded, maximal cardiopulmonary treadmill exercise testing using a modified Balke protocol. Breath-by-breath respiratory gas analysis and peak exercise oxygen consumption (VO2max) measurements were obtained. Immediately after exercise and at 3,6 minutes into recovery, repeat Doppler echocardiographic data were obtained for determination of LVDF parameters. VO2max (44 ± 6.3 vs 27 ± 4.2 mllkglmin, P< 0.001), oxygen consumption at anaerobic threshold (35 ± 5.4 vs 24 ± 3.8 mllkglmin, P< 0.001), exercise duration (24 ± 3 vs 12 ± 6 minutes, P< 0.001), and left ventricular mass index (61 ± 13 vs 51 ± 7.8 kglm2, P< 0.05) were greater in endurance athletes than in sedentary control subjects, whereas body mass index was lower (22 ± 1.7 vs 26 ± 3.4 kglm2, P< 0.001). No differences in any of the LVDF characteristics were observed between the groups with the exception of a trend toward a lower atrial filling fraction at rest in the endurance athlete group versus the control subjects (P= 0.07). High-intensity endurance exercise training promotes exceptional peak exercise oxygen consumption and cardiovascular stamina but does not appear to alter normative aging effects on left ventricular diastolic function. (ECHOCARDIOGRAPHY, Volume 17, January 2000) [source] The effect of nightshift on emergency registrars' clinical skillsEMERGENCY MEDICINE AUSTRALASIA, Issue 3 2010Leonie Marcus Abstract Objective: The effect of nightshift on ED staff performance is of clinical and risk-management significance. Previous studies have demonstrated deterioration in psychomotor skills but the present study specifically assessed the impact of nightshift on clinical performance. Methods: The ED registrars in a tertiary hospital were enrolled in a prospective observational study and served as their own controls. During nightshift, subjects were presented simulated scenarios and tested with eight clinical questions developed to Fellowship examination standard. Matched scenarios and questions for the same subjects during dayshift served as controls. Two investigators, blinded to subject identity and the setting in which questions were attempted, independently collated answers. Results: Of 22 eligible subjects, all were recruited; four were excluded owing to incomplete data. A correlation of 0.99 was observed between the independent scoring investigators. Of a possible score of 17, the median result for nightshift was 9.5 (interquartile range: 8,11); corresponding value for dayshift was 12 (interquartile range: 10,13); P= 0.047. Conclusion: Nightshift effect on clinical performance is anecdotally well known. The present study quantifies such effects, specifically for the ED setting, and paves the way for focused research. The implications for clinical governance strategies are significant, as the fraternity embraces the mandate to maintain quality emergency care 24 h per day. [source] Ultrasound-assisted peripheral vascular access in a paediatric EDEMERGENCY MEDICINE AUSTRALASIA, Issue 2 2010Ed Oakley Abstract Objectives: To assess the implementation and utility of US for assisting peripheral venous access in a paediatric ED. Methods: A prospective, observational study of a convenience sample comparing the landmark and US-guided technique for peripheral vascular access in children from July 2006 to February 2007. Clinicians involved under went 3 months of training in US physics and with practical models. Clinicians estimated the degree of difficulty of insertion (using a Likert scale) before each line placement. Data including time of procedure and success or failure were collected, using a standardized clinical record form, by an observing researcher. Results: A total of 84 patients were enrolled. There were 61 line placement episodes in the landmark group (with 253 attempts), and 38 in the US group (with 90 attempts). US recorded slightly higher success per attempt overall (42% vs 38%, P= 0.08), and performed better in the patients with difficult access (success 35% vs 18%, P= 0.003). US attempts took longer than landmark attempts (2 min 15 s vs 4 min, P < 0.001). Conclusion: The US guidance may improve the success rate of peripheral vascular access in children rated to have difficult or very difficult vascular access. [source] Investigating moderate to severe paediatric trauma in the Auckland regionEMERGENCY MEDICINE AUSTRALASIA, Issue 2 2010Louise Couch Abstract Objective: To investigate differences between paediatric patients with moderate to severe trauma admitted from two paediatric ED, with respect to: demographics, patterns of presentation, mechanism of injury, injury severity scores (ISS), interventions and outcome. Method: Retrospective cohort study. Moderate to severe trauma was defined as ISS >9. Paediatric patients admitted to hospital via Starship Children's Emergency or KidzFirst ED, with trauma from 1 May 2003 to 30 April 2004, with ISS >9 were identified using multiple databases. The charts were reviewed and data collected included: demographics, hospital of first presentation, diagnoses, ISS, Paediatric trauma score (PTS), Glasgow coma score (GCS), ventilator hours, length of admission, survival and discharge destination. Descriptive statistics with 95% confidence intervals, Mann,Whitney U -test, ,2 -test and Fisher's exact test were used as appropriate. Results: A total of 393 children with moderate to severe trauma were identified using initial search strategies. Of these, 82 children met the inclusion and exclusion criteria for the study; 42 children were admitted via KidzFirst ED and 40 via Starship Children's ED. There was no statistically significant difference in ISS (P= 0.86), PTS (P= 0.11), GCS (P= 0.62), hours on a ventilator (P= 0.28) and length of stay (P= 0.87) between children admitted from Starship or KidzFirst ED. Conclusion: This study suggests that there are no differences in the numbers or severity of paediatric trauma patients admitted from the Starship and KidzFirst ED. This indicates triage is to the closest ED despite having a tertiary referral centre for paediatric trauma available in Auckland City. [source] Paracetamol versus ibuprofen: A randomized controlled trial of outpatient analgesia efficacy for paediatric acute limb fracturesEMERGENCY MEDICINE AUSTRALASIA, Issue 6 2009Michael Shepherd Abstract Paediatric limb fracture is a common injury that presents frequently to the ED. The primary objective of the present study was to determine whether ibuprofen provides better analgesia than paracetamol for paediatric patients discharged with acute limb fractures. A prospective, randomized controlled study was conducted in a children's ED. Children aged 5,14 years with an acute limb fracture were randomized to be prescribed paracetamol 15 mg/kg/dose every 4 h or ibuprofen 10 mg/kg/dose every 8 h. Objective (child-reported) pain scores using the ,Faces' pain scale were measured over a 48 h period. Child-reported pain did not differ significantly between the paracetamol and ibuprofen groups (mean pain score paracetamol 2.8 [95% CI 2.4,3.4]vs 2.7 [95% CI 2.1,3.3], P= 0.73). Parent-reported sleep quality did not differ between the two groups (P= 0.78). Child-reported pain score decreased over the 48 h of measurement (P < 0.0001). There were no significant differences in side-effects detected between the two groups. The present study shows that in the outpatient paediatric population, ibuprofen does not provide better analgesia than paracetamol. Pain from an acute fracture can be managed by regular simple oral analgesia and immobilization. [source] Knowledge and attitude towards paediatric cardiopulmonary resuscitation among the carers of patients attending the Emergency Department of the Children's Hospital at WestmeadEMERGENCY MEDICINE AUSTRALASIA, Issue 5 2009Jonathan Cu Abstract The present study aimed to describe the knowledge and attitudes of parents and carers in performing cardiopulmonary resuscitation on infants and children. A self-administered questionnaire distributed to a convenience sample of parents and carers attending the Emergency Department of The Children's Hospital at Westmead, Australia from February to March 2008. Main outcome measures were the prevalence of previous cardiopulmonary resuscitation training, willingness and confidence to perform cardiopulmonary resuscitation on infants and children compared with adults, and an objective assessment of knowledge of current resuscitation guidelines. A total of 348 parents and carers were surveyed; 53% had received previous cardiopulmonary resuscitation training, 75% prior to the previous year. There was no significant difference on their willingness to perform cardiopulmonary resuscitation on an adult versus a child (75.6% and 75.8% respectively, P= 0.870). However, 81% were willing to perform cardiopulmonary resuscitation on a relative whereas only 64% were willing to perform cardiopulmonary resuscitation on a stranger (P < 0.001). Respondents were moderately confident in delivering cardiopulmonary resuscitation to a collapsed child; mean score of 2.9 on 5-point Likert scale. Only 11% of respondents knew the correct rate for chest compressions and the ratio of compressions to ventilations; 8% had performed cardiopulmonary resuscitation in a real situation. Parents and carers are willing to perform cardiopulmonary resuscitation, especially on family members. However, their knowledge of the current guidelines was poor. More public education is required to update those with previous training and to encourage those who haven't to be trained. [source] Stylet penetration behavior resulting in inoculation of a semipersistently transmitted closterovirus by the whitefly Bemisia argentifoliiENTOMOLOGIA EXPERIMENTALIS ET APPLICATA, Issue 2 2002D.D. Johnson Abstract The electrical penetration graph (EPG) technique was used to determine what part of stylet penetration behavior by the whitefly vector, Bemisia argentifolii Bellows & Perring (Homoptera: Aleyrodidae), is lettuce chlorosis virus (LCV) inoculated in the host plant Malva parviflora L. LCV is a semipersistently-transmitted closterovirus. Since closteroviruses generally are found in the phloem of their plant hosts, this study tested the hypothesis that virus inoculation occurs during the phloem phase of stylet penetration behavior. Virus-exposed whiteflies were allowed to feed on uninfected host plants, and the whiteflies were divided into two experimental groups: group 1 attained phloem phase on the uninfected plants, and group 2 did not attain phloem phase. Two series of tests were conducted, one where whiteflies were manipulated so that the amount of time spent in non-phloem phase stylet penetration behaviors was similar between group 1 and group 2, and a second series of tests where whiteflies were manipulated so that the number of intracellular punctures made during stylet penetration was similar between group 1 and group 2. Both series of tests indicated that virus inoculation took place primarily during phloem phase. Considering only individual whiteflies shown to be capable of transmitting virus, 11 of 23 whiteflies (48%) in the phloem phase treatment successfully inoculated the virus whereas only one of 19 whiteflies (5%) in the non-phloem phase treatment successfully inoculated the virus (P= 0.00008). [source] Effect of age and training on murmurs of atrioventricular valvular regurgitation in young ThoroughbredsEQUINE VETERINARY JOURNAL, Issue 3 2000L. E. Young Summary Cardiac auscultation was carried out on 111 Thoroughbred horses age 2,5 years to test the hypothesis that athletic training might influence the development of atrioventricular (AV) valve regurgitation in young Thoroughbreds. Murmurs of valvular regurgitation were identified and graded on a 1,6 scale. There were 2 sources of auscultation data: 1) 55 2-year-old horses that were examined by auscultation before training commenced and 9 months later when at race fitness; 2) 56 horses age 2,5 years that were examined on one occasion only (25 2-year-olds, 23 3-year-olds, five 4-year-olds and five 5-year olds). All horses in the second data set were in full training and racing regularly at the time of the examination. To conclude the study, 35 horses were selected randomly from both groups of horses and examined with colour-flow Doppler echocardiography. The aim of the final part of the study was to check specificity and sensitivity of auscultation for detection of AV valve murmurs and therefore validate the auscultation findings. Priorto training, the prevalence in 2-year-old racehorses of murmurs of mitral regurgitation and tricuspid regurgitation was 7.3% (4/55) and 12.7% (7/55), respectively. After training, the prevalence proportions increased to 21.8% (12/55) and 25.5% (14/55). After training, one horse developed a murmur characteristic of aortic regurgitation. The differences in murmur prevalence were statistically significant for mitral and tricuspid regurgitation (paired t test results: mitral regurgitation, P = 0.019; tricuspid regurgitation, P = 0.007), as were the differences in mean murmurgrade (P= 0.018 and P= 0.0006, respectively). There were no significant effects of age on the prevalence of valvular regurgitation in 56 horses examined at race fitness. Auscultation was a specific (specificity 100%) and reasonably sensitive method for detection of murmurs of mitral and tricuspid regurgitation (mitral regurgitation: positive predictive value 100%, negative predictive value 84%, tricuspid regurgitation: positive predictive value 100%, negative predictive value 65%). These data suggest that the prevalence and grade of murmurs of mitral and tricuspid valvular regurgitation increase in 2-year-old Thoroughbreds after 9 months of athletic training. Whereas the effects of age and growth on the prevalence of murmurs cannot be ruled out from these data, this study suggests that there is an influence of athletic training on the development of atrioventicular valvular regurgitation in flat-racing Thoroughbreds. [source] Plasma angiopoietin-1, angiopoietin-2 and Tie-2 in breast and prostate cancer: a comparison with VEGF and Flt-1EUROPEAN JOURNAL OF CLINICAL INVESTIGATION, Issue 10 2003G. J. Caine Abstract Background, Angiogenesis is essential for tumour growth and metastasis, and is coordinated by several classes of growth factors mediating their effect through receptors linked, in turn, to tyrosine kinase. These growth factors include angiopoietin-1 (Ang-1), angiopoietin-2 (Ang-2) and vascular endothelial growth factor (VEGF), which act through receptors Flt-1 and Tie-2. Materials and methods, In order to further determine abnormalities in levels of Ang-1, Ang-2, Tie-2, sFlt-1 and VEGF in human cancer (and their interrelationships), these molecules were measured in plasma from 30 patients with breast cancer, 30 patients with prostate cancer and 12 healthy controls per cancer group. Results, In breast cancer, levels of Ang-1 (P = 0·0005), Ang-2 (P = 0·0173), Tie-2 (P = 0·0001), and VEGF (P = 0·0001) were all significantly raised, and plasma levels of sFlt-1 (P = 0·045) were significantly reduced compared with controls. However, in prostate cancer, only levels of VEGF and Tie-2 were significantly higher (both P= 0·001). There were no significant differences between levels of any molecule between the two groups of cancer. The only difference between the healthy control groups was lower Ang-1 in the women compared with men. Significant correlations were found between levels of Ang-1 and Tie-2 both in breast (r = 0·498, P= 0·005) and prostate cancer (r = 0·643, P= < 0·001). Angiopoietin-1 was also positively correlated with Ang-2 in both breast (r = 0·422, P= 0·02) and prostate cancer (r = 0·543, P= 0·002). Conclusions, Abnormal levels of Ang-1, Ang-2 and their receptor, Tie-2, are present in breast and prostate cancer, and their interrelationships may be important in the pathophysiology of these conditions. [source] Prognostic significance of soluble interleukin-2 receptor levels in patients with dilated cardiomyopathyEUROPEAN JOURNAL OF CLINICAL INVESTIGATION, Issue 6 2003C. J. Limas Abstract Background Activation of T lymphocytes is thought to mediate myocardial dysfunction in dilated cardiomyopathy (CMP), probably through cytotoxic cytokines, but its value as a prognostic factor has not been evaluated. Methods For 2 years we prospectively followed 76 patients (65 males, 11 females, age 49 ± 7 years) with CMP and New York Heart Association(NYHA) Class II,III heart failure; left ventricular (LV) function was assessed echocardiographically. Thirty-three patients (28 males, five females, age 52 ± 6 years) with ischaemic heart disease (IHD) and similar NYHA and LV function characteristics were used as controls. Serum sIL-2R levels, peripheral blood lymphocyte proliferation (basal, + concanavalin A) and HLA-DQB1 genotyping was carried out in all patients. Results The CMP patients had increased sIL-2R levels (1259 ± 130 pg mL,1) compared with the IHD patients (703 ± 80 pg mL,1, P < 0·01, only 3 > 800 pg mL,1). In the CMP patients, there was a significant (r = +0·45, P= 0·04) correlation between sIL-2R and the LV end-diastolic diameter but not with the LV ejection fraction or NYHA Class. During the 24-month follow up, 17 of the CMP patients had an adverse clinical course (death, need for cardiac transplantation, or worsening heart failure). Of these, 14 (75%) had elevated (, 800 pg mL,1) sIL-2R levels (Group I) compared with only five (6%) with a stable clinical course (Group II). Neither [3H] thymidine incorporation into the peripheral blood lymphocytes nor the excess of HLA-DQB1-30 histidine homozygotes in the Group I patients (38% vs. 17%, P < 0·05) could predict the clinical outcome. Conclusion Increased sIL-2R levels in CMP patients are an independent predictor of a more aggressive clinical course. [source] ANTHROPOGENIC EFFECTS ON POPULATION GENETICS OF PHYTOPHAGOUS INSECTS ASSOCIATED WITH DOMESTICATED PLANTSEVOLUTION, Issue 12 2007Nadir Alvarez The hypothesis of isolation by distance (IBD) predicts that genetic differentiation between populations increases with geographic distance. However, gene flow is governed by numerous factors and the correlation between genetic differentiation and geographic distance is never simply linear. In this study, we analyze the interaction between the effects of geographic distance and of wild or domesticated status of the host plant on genetic differentiation in the bean beetle Acanthoscelides obvelatus. Geographic distance explained most of the among-population genetic differentiation. However, IBD varied depending on the kind of population pairs for which the correlation between genetic differentiation and geographic distance was examined. Whereas pairs of beetle populations associated with wild beans showed significant IBD (P < 10,4), no IBD was found when pairs of beetle populations on domesticated beans were examined (P= 0.2992). This latter result can be explained by long-distance migrations of beetles on domesticated plants resulting from human exchanges of bean seeds. Beetle populations associated with wild beans were also significantly more likely than those on domesticated plants to contain rare alleles. However, at the population level, beetles on cultivated beans were similar in allelic richness to those on wild beans. This similarity in allelic richness combined with differences in other aspects of the genetic diversity (i.e., IBD, allelic diversity) is compatible with strongly contrasting effects of migration and drift. This novel indirect effect of human actions on gene flow of a serious pest of a domesticated plant has important implications for the spread of new adaptations such as resistance to pesticides. [source] INBREEDING IN THE SEYCHELLES WARBLER: ENVIRONMENT-DEPENDENT MATERNAL EFFECTSEVOLUTION, Issue 9 2004David S. Richardson Abstract The deleterious effects of inbreeding can be substantial in wild populations and mechanisms to avoid such matings have evolved in many organisms. In situations where social mate choice is restricted, extrapair paternity may be a strategy used by females to avoid inbreeding and increase offspring heterozygosity. In the cooperatively breeding Seychelles warbler, Acrocephalus sechellensis, neither social nor extrapair mate choice was used to avoid inbreeding facultatively, and close inbreeding occurred in approximately 5% of matings. However, a higher frequency of extra-group paternity may be selected for in female subordinates because this did reduce the frequency of mating between close relatives. Inbreeding resulted in reduced individual heterozygosity, which, against expectation, had an almost significant (P= 0.052), positive effect on survival. Conversely, low heterozygosity in the genetic mother was linked to reduced offspring survival, and the magnitude of this intergenerational inbreeding depression effect was environment-dependent. Because we controlled for genetic effects and most environmental effects (through the experimental cross-fostering of nestlings), we conclude that the reduced survival was a result of maternal effects. Our results show that inbreeding can have complicated effects even within a genetic bottlenecked population where the "purging" of recessive alleles is expected to reduce the effects of inbreeding depression. [source] | ||||||||||||||||||||||||||||||||||||||||