"Isolation by Gentes with Asymmetric Migration" shapes the genetic structure of the common cuckoo in China.

Amid coevolutionary arms races between brood parasitic birds and their diverse host species, the formation of host-specific races, or gentes, has drawn significant research focus. Nevertheless, numerous questions about gentes evolutionary patterns persist. Here, we investigated the potential for gentes evolution across multiple common cuckoo (Cuculus canorus) populations parasitizing diverse host species in China. Using maternal (mitochondrial and W-linked DNA) and biparental (autosomal and Z-linked DNA) markers, we found consistent clustering of cuckoo gentes (rather than geographical populations) into distinct clades in matrilineal gene trees, indicating robust differentiation. In contrast, biparental markers indicated intermixing of all gentes, suggesting asymmetric gene flow regardless of geography. Unlike the mitonuclear discordance commonly resulting from incomplete lineage sorting, adaptive introgression, or demographic disparities, the observed pattern in brood parasitic cuckoos might reflect biased host preferences between sexes. We hereby present the "Isolation by Gentes with Asymmetric Migration" model. According to this model, the maternal line differentiation of the common cuckoo in China is potentially driven by host preferences in females, whereas males maintained the integrity of the cuckoo species through random mating. To achieve this, cuckoo males could perform flexible migration among gentes or engage in early copulation with females before reaching the breeding sites, allowing female cuckoos to store sperm from various gentes. Future studies collecting additional samples from diverse cuckoo gentes with overlapping distribution and investigating the migratory and copulation patterns of each sex would enhance our understanding of sex-biased differentiation among cuckoo populations in China.

Personality-dependent nest site selection and nest success during incubation in wild chestnut thrushes.

In birds, little is known about how individuals choose nest sites based on their personality traits. Here, we investigate whether a female's personality (activity and breathing rate) can affect patterns of nest site selection at different spatial scales in a wild population of chestnut thrush (Turdus rubrocanus) and determine whether nest site characteristics and female personality traits affect clutch size and nest success during incubation. We found that neither activity nor breathing rate were associated with large-scale nesting habitat variables. At the fine-scale level, more active females chose nest sites with greater nest lateral concealment. Females with higher breathing rates laid smaller clutch sizes than individuals with lower breathing rates. Nests of females with lower breathing rate had higher nest success during incubation. This work highlights the relationships between personality and nest site selection in birds, and the important role of female personality traits in reproductive success.

Switching costs in stochastic environments drive the emergence of matching behaviour in animal decision-making through the promotion of reward learning strategies.

A principle of choice in animal decision-making named probability matching (PM) has long been detected in animals, and can arise from different decision-making strategies. Little is known about how environmental stochasticity may influence the switching time of these different decision-making strategies. Here we address this problem using a combination of behavioral and theoretical approaches, and show, that although a simple Win-Stay-Loss-Shift (WSLS) strategy can generate PM in binary-choice tasks theoretically, budgerigars (Melopsittacus undulates) actually apply a range of sub-tactics more often when they are expected to make more accurate decisions. Surprisingly, budgerigars did not get more rewards than would be predicted when adopting a WSLS strategy, and their decisions also exhibited PM. Instead, budgerigars followed a learning strategy based on reward history, which potentially benefits individuals indirectly from paying lower switching costs. Furthermore, our data suggest that more stochastic environments may promote reward learning through significantly less switching. We suggest that switching costs driven by the stochasticity of an environmental niche can potentially represent an important selection pressure associated with decision-making that may play a key role in driving the evolution of complex cognition in animals.

[An analysis of failure and safety profiles of capsule endoscopy].

OBJECTIVE: To analyse the incidence of technical breakdown and clinical problem leading to the failure of capsule endoscopy examination and their influence on the diagnosis and to evaluate its feasibility and safety in special patient population. METHODS: A retrospective study of 300 consecutive patients referred to Renji Hospital for evaluation of suspected small bowel diseases between May 2002 and May 2006 was done. This included 300 consecutive patients. The median age of the patients was 51 y (range, 3 - 91 y). The young children group was defined as less than 10 years and the elderly group as more than 80 years. Technical problems were those related to the functioning of the equipment and clinical problems were those related to the patient. The incidence and the type of above-mentioned events and their influence on the diagnosis were analyzed. The safety and feasibility of the capsule endoscopy procedure were evaluated in the young children group, elderly group and patients with pacemakers, gastrectomy and Billroth II gastrojejunostomy, intestinal diverticula, Crohn's disease and polyp of small intestine. RESULTS: A total of 300 patients were involved. The incidence of technical problems was 1.3%, including one case of failing in activating the capsule, one case of failing in loading the data and two cases of short life of battery. Failure of diagnosis was encountered in two cases. The incidence of clinical problems was 33.0% (99 cases) and they caused 35.4% (35 cases) failure of diagnosis in the 99 cases. Three patients in the young children group were unable to swallow the capsule and endoscope-guided overtube technique was used with success in all. In the elderly group, the incidence of capsule retaining in the oesophagus and stomach was as high as 23.0%. In two patients with pacemaker no interference between pacemaker and capsule was detected. In two patients with Billroth II gastrojejunostomy no capsule retention occurred. In 16 patients with diverticulum, capsule retention occurred in 1 case (6.0%). In 42 patients with Crohn's disease, capsule retention occurred in 5 cases. No acute gastrointestinal obstruction was found in the 42 patients with Crohn's disease and in 5 patients with polyp of small intestine. CONCLUSIONS: With capsule endoscopy technical mistakes causing failure were very rare. The majority of the clinical problems were related to the inability capsule to reach the colon during the recording time. Capsule endoscopy provides a well-tolerated, safe and effective tool to investigate the gastrointestinal diseases, especially some small bowel diseases.

Purgative bowel cleansing combined with simethicone improves capsule endoscopy imaging.

AIM: To evaluate the effects of the various methods of small bowel preparation on the quality of visualization of the small bowel and the gastrointestinal transit time of capsule endoscopy (CE). METHODS: Ninety patients referred for CE were prospectively randomized to three equal groups according to the preparation used: (a) a control group, in which patients were requested to drink 1 L of clear liquids only, 12 h before the examination; (b) a purgative group, in which patients were requested to ingest 1 L of a polyethylene glycol (PEG)/electrolyte solution only, 12 h before the examination; or (c) a purgative combined with simethicone group (P-S group), in which patients were requested to ingest 1 L of PEG, 12 h before the examination, and 300 mg of simethicone, 20 min before the examination. Effects of the different bowel preparations on the gastric transit time (GTT), small bowel transit time (SBTT), examination completion rate, quality of images of the entire small intestine, and cleansing of the proximal small bowel and distal ileum were evaluated. RESULTS: The number of patients with "adequate" cleansing of the entire small intestine was 17 in the P-S group, 12 in the purgative group, and seven in the control group (P= 0.002). The P-S group had significantly better image quality than the control group (P= 0.001). The P-S group had significantly better image quality for the proximal small bowel (segment A [Seg A]) than the control group (P= 0.0001). Both the P-S group (P= 0.0001) and the purgative group (P= 0.0002) had significantly better image quality for the distal ileum (segment B [Seg B]) than the control group; the P-S group had significantly better image quality than the purgative group as well (P= 0.0121). Gastrointestinal transit time was not different among the three groups, nor was the examination completion rate. CONCLUSIONS: Purgative bowel cleansing combined with simethicone before CE improved the quality of imaging of the entire small bowel as well as the visualization of the mucosa in the proximal and distal small intestine.

Best candidates for capsule endoscopy for obscure gastrointestinal bleeding.

BACKGROUND AND AIM: Capsule endoscopy (CE) has an important role in the diagnosis of patients with obscure gastrointestinal bleeding. However, there was still controversy regarding the best candidates for CE. The present retrospective study aimed to access the best candidates for CE. METHODS: There were 91 consecutive patients referred to the present study for 94 CE examinations from May 2002 to January 2005. They were divided into two groups (41 with active bleeding, and 50 with previous bleeding). RESULTS: The CE findings were positive in 74.7%, suspicious in 11% of cases and negative in 14.3% of cases, respectively. The positive and suspected positive yield of CE were 75.6% and 19.5% in the active bleeding group, 74% and 4% in the previous bleeding group (P = 0.01), 75.7% and 21.6% in the overt bleeding group, 75% and 0% in the occult bleeding group (P = 0.206), 89.7% and 3.4% in patients who bled 2 weeks previously, 52.38% and 4.76% in patients who bled >2 weeks previously (P = 0.003), 75.6% and 19.5% in active bleeding group, 89.7% and 3.4% in patients who bled 2 weeks ago (P = 0.128). CONCLUSIONS: The best candidates for the procedure are those with active bleeding, or active bleeding in the previous 2 weeks.

Relationship between fecal lactoferrin and inflammatory bowel disease.

OBJECTIVE: Lactoferrin as a glucoprotein that can reflect the activity of neutrophil leukocytes is a specific and sensitive indicator in the evaluation of intestinal inflammation. The aim of this study was to evaluate the relationship between fecal lactoferrin and intestinal inflammation by quantitative analysis and the effect of fecal lactoferrin in measuring the activity of inflammatory bowel disease (IBD) including ulcerative colitis (UC) and Crohn's disease (CD). MATERIAL AND METHODS: A total of 177 fresh stool samples were collected from 42 active UC, 17 inactive UC, 13 active CD, 5 inactive CD, 41 infectious bowel disease, 25 irritable bowel syndrome (IBS) and 34 healthy volunteers. IBD-SCAN was used quantitatively to measure the level of fecal lactoferrin. A modified Harvey-Bradshaw Active Index was used to evaluate the activity of IBD. RESULTS: Fecal lactoferrin was 3.15+/-1.60 microg/g in healthy volunteers, 2.54+/-1.49 microg/g in IBS, 83.3+/-29.9 microg/g in infectious bowel disease, 1126.29+/-431.21 microg/g in active UC, 1035.25+/-456.59 microg/g in active CD, 96.58+/-82.46 microg/g in inactive UC and 133.52+/-88.89 microg/g in inactive CD. Fecal lactoferrin was significantly higher in active IBD than in inactive IBD, IBS and infectious bowel disease. The sensitivity and specificity of fecal lactoferrin were 92% and 88%, respectively, for UC, and 92% and 80%, respectively, for CD. CONCLUSIONS: Fecal lactoferrin is a sensitive and specific marker in measuring the activity of IBD. It provides us with a valid method in discriminating between inflammatory and non-inflammatory bowel disease. In addition, an elevated fecal lactoferrin level can lead us to exclude IBS in clinical practice.

Effect of mosapride on gastrointestinal transit time and diagnostic yield of capsule endoscopy.

BACKGROUND AND AIM: Since its introduction, capsule endoscopy (CE) has made it possible to visualize the small intestine mucosa directly. However, owing to the limited battery life, only 60-80% of the capsules could reach the cecum and would possibly affect the diagnostic yield. The aim of this study was to determine the effect of oral mosapride on gastrointestinal transit time and the diagnostic yield of CE. METHOD: Sixty patients were involved in this randomized, prospective and controlled study. The patients were randomly allocated to groups receiving either mosapride citrate or nothing. Patients in the mosapride group (n = 30) received 10 mg mosapride citrate 1 h before CE examination, while patients in the control group (n = 30) received no preparation. The gastrointestinal transit time, the number of CE reaching the cecum, and the diagnostic yield of each group were assessed in a single-blinded fashion. RESULT: Gastric emptying time was significantly shorter in the mosapride group than in the control group (13.5 min vs 34 min P = 0.035). Compared with the control group, the complete transit rate was significantly higher in the mosapride group (93.3% vs 66.7% P = 0.021). There was no significant difference between the two groups on the small bowel transit time and diagnostic yield. CONCLUSION: Mosapride citrate accelerates the gastric emptying and completion rate of small bowel examination in patients undergoing CE.

The role of capsule endoscopy combined with double-balloon enteroscopy in diagnosis of small bowel diseases.

BACKGROUND: The diagnosis of small bowel diseases remains relatively inefficient using traditional imaging techniques. Capsule endoscopy (CE) and double-balloon enteroscopy (DBE) are two novel methods of enteroscopy for examining the entire small bowel. The aim of this study was to evaluate the detection rate and diagnostic accuracy of CE and DBE in patients with suspected small bowel diseases and to investigate the clinical significance of combined use of these two novel modalities. METHODS: Two hundred and eighteen patients were evaluated for suspected small bowel disease, including 116 with obscure gastrointestinal bleeding and 102 with obscure abdominal pain or chronic diarrhea. One hundred and sixty-five out of these patients underwent CE first and 53 patients underwent DBE (under anesthesia with propofol) first. DBE was recommended after negative or equivocal evaluation on CE and vise versa. Introduction of the endoscope during DBE was either orally or anally and the patients were referred for a second procedure using the opposite route several days later when no abnormalities were found on the first procedure. The detection rates, diagnostic accuracy, tolerance and frequency of adverse events of these two modalities were then analyzed. RESULTS: Failure of the procedure was seen in one patient with CE and in two patients with DBE. Sixty-four DBE procedures were carried out in 51 patients; by the oral route in 34 cases, the anal route in 4 and both routes in 13 cases. The overall detection rate of small bowel diseases using CE (72.0%, 118/164) was superior to that with DBE (41.2%, 21/51); chi(2) = 16.1218, P < 0.0001. The diagnostic rate (51.8%, 85/164) was also higher than that with the latter procedure (39.2%, 20/51), but was not significantly different (chi(2) = 2.4771, P > 0.05). Furthermore, the detection rate of small bowel diseases in patients with obscure gastrointestinal bleeding using CE (88.0%, 88/100) was superior to that of DBE (60.0%, 9/15); chi(2) = 7.7457, P = 0.0054. Lesions were detected by DBE in 1 out of 4 patients in whom CE had a negative result. Suspected findings by CE were confirmed by DBE combined with biopsy in 12 out of 15 patients. On the other hand, small bowel lesions were identified by CE in all 3 patients after negative evaluations by DBE. There were no severe complications during or after either of the two procedures. CONCLUSIONS: The detection rate of small bowel diseases by CE is very high. CE should be selected for the initial diagnosis in patients with suspected small bowel diseases, especially in patients with obscure gastrointestinal bleeding. DBE appears to be inferior to CE in the diagnosis of small bowel diseases. However, it was shown that abnormalities could still be identified by DBE in patients with normal images or used to confirm suspected findings from CE. DBE can also serve as a good complementary approach after an initial diagnostic imaging using CE.

Clinical application of wireless capsule endoscopy in pediatric patients for suspected small bowel diseases.

Capsule endoscopy (CE) has been demonstrated to be safe and well tolerated in adults with suspicion of small intestinal diseases with negative results of gastroscopy and colonoscopy. However, its value in pediatric patients has not yet been well studied. This study aimed to evaluate the results and safety of CE in pediatric patients with suspicion of small bowel disorders. There were 16 consecutive children and adolescents (12 boys, 4 girls) and 15 adults (9 men, 6 women) referred to us for suspected small bowel diseases from August 2002 to September 2005. Among the pediatrics, six patients were less than 10 years old. Technique for capsule placement, gastric transit time, small bowel transit time, excretion time of capsule endoscopy, capsule findings, and complications were recorded. All 16 pediatric patients described that the capsule was easy to swallow except for three children. Finally we delivered the capsule under gastroscopy with overtube for these three children. No capsule retention occurred during our study. Median recording time was 7 h 44 min (range 6 h 51 min-9 h 11 min). Median gastric transit time was 83.5 min (range 4-296 min). Median small bowel transit time was 270 min (range 142-484 min). Median excretion time of capsule was 33.9 h (range 12-96 h). There was no significant difference in excretion time of capsule, gastric transit time and small bowel transit time between pediatric patients and adult patients (P > 0.05). CE was positive in 12 patients, including Crohn's disease (4), hemangioma (2), angiodysplasia (2), Meckel diverticulum (1), polyp (1), aphthous ulcer in ascending colon (1), and cobblestone appearance of ileal mucosa. CE has been performed safely in a small series of pediatric patients after ingestion or endoscopic placement of the capsule. The high yield of abnormal findings was comparable to those of adult patients.

[Clinical application of wireless capsule endoscopy in pediatric and adolescent patients].

OBJECTIVE: Capsule endoscopy (CE) has been demonstrated to be safe and well tolerated in adults. However, its value in pediatric patients has not been well studied. The present study aimed to evaluate the safety and effectiveness of CE in pediatric patients with suspicious small bowel disorders. METHODS: Fifteen children and adolescents (less than 18 years) were referred to our study for suspected small bowel diseases from Aug. 2002 to May 2005. They aged from 3 to 18 years. Among them, 5 patients were less than 10 years old. The range of weight was from 17 to 83 kg and height was from 49 to 176 cm. Clinical indications included obscure gastrointestinal bleeding (n = 12) and abdominal pain (n = 3). All the patients had normal results on upper and lower gastrointestinal examinations before they underwent CE. The procedures for capsule placement, gastric transit time, small bowel transit time, the average time of the elimination of the capsule, capsule findings, and complications were recorded. RESULTS: All the patients described that the capsule was easy to swallow except 3 youngest children. Finally the capsule was delivered via gastroscopy with overtube for these three children under intravenous anesthesia. No capsule retention occurred during the study. Median recording time was (464 +/- 40) min. In 5 patients, the capsule did not pass the ileal valve by the end of the recording time. Median gastric transit time was (85 +/- 90) min. Median small bowel transit time was (283 +/- 106) min. The average time of the elimination of the capsule was (34.3 +/- 21.8) h. The detective yield of CE was 80%. These positive findings included Crohn's disease (5), hemangioma (2), angiodysplasia (2), Meckel diverticulum (1), polyp (1), and granulomatous lesions (1). CONCLUSION: CE was performed safely in pediatric patients after ingestion or endoscopic placement of the capsule. The high yield of abnormal findings was comparable to those of adult patients.

Capsule endoscopy and push enteroscopy in the diagnosis of obscure gastrointestinal bleeding.

BACKGROUND: In obscure gastrointestinal (GI) bleeding, it is often difficult to detect the bleeding sites located in the small bowel with conventional radiological, scintigraphic or angiographic techniques. Push enteroscopy and capsule endoscopy are currently considered to be the most effective diagnostic procedures. The aim of this study was to compare the detection rates between capsule endoscopy and push enteroscopy. METHODS: From May 2002 through January 2003, we prospectively examined by capsule endoscopy 39 patients with suspected small bowel diseases, in particular GI bleeding of unknown origin in Renji Hospital. Among them, 32 complained of obscure recurrent GI bleeding. Between January 1993 and October 1996, we used push enteroscopy on 36 patients who suffered from unexplained GI bleeding. All patients had prior normal results on gastroscopy, colonoscopy, small bowel barium radiography, scintigraphy and/or angiography. RESULTS: M2A capsule endoscopy disclosed abnormal small bowel findings in 26 (82%) out of 32 patients. Twenty-one of them had significant pathological findings explaining their clinical disorders. Diagnostic yield was therefore 66% (21 of 32 patients). Definite bleeding sites diagnosed by capsule endoscopy in 21 patients included angiodysplasia (8), inflammatory small-bowel (5), small-bowel polyps (4), gastrointestinal stromal tumour (2), carcinoid tumour and lipoma (1), and hemorrhagic gastritis (1). Push enteroscopy detected the definite sources of bleeding in 9 (25%) of the 36 patients. Patients with definite bleeding sources included angiodysplasias (2), leiomyosarcoma (2), leiomyoma (1), lymphoma (1), Crohn's disease (1), small-bowel polyps (1) and adenocarcinoma of ampulla (1). Suspected bleeding sources were shown by push enteroscopy in two additional patients (6%), and in other five patients (16%) by capsule endoscopy. CONCLUSIONS: The present study of patients with obscure GI bleeding showed that capsule endoscopy significantly superior to push enteroscopy in detecting GI bleeding (P < 0.001). Capsule endoscopy is safe and painless, and should become the initial diagnostic choice for patients with obscure GI bleeding.

Capsule endoscopy in diagnosis of small bowel Crohn's disease.

AIM: To evaluate the effectiveness of wireless capsule endoscopy in patients with suspected Crohn's disease (CD) of the small bowel undetected by conventional modalities, and to determine the diagnostic yield of M2A Given Capsule. METHODS: From May 2002 to April 2003, we prospectively examined 20 patients with suspected CD by capsule endoscopy. The patients had the following features: abdominal pain, weight loss, positive fecal occult blood test, iron deficiency anaemia, diarrhoea and fever. All the patients had normal results in small bowel series (SBS) and in upper and lower gastrointestinal endoscopy before they were examined. Mean duration of symptoms before diagnosis was 6.5 years. RESULTS: Of the 20 patients, 13 (65%) were diagnosed as CD of the small bowel according to the findings of M2A Given Capsule. The findings detected by the capsule were mucosal erosions (2 patients), aphthas (5 patients), nodularity (1 patient), large ulcers (2 patients), and ulcerated stenosis (3 patients). The distribution of the lesions was mainly in the distal part of the small bowel, and the mild degree of lesions was 54%. CONCLUSION: Wireless capsule endoscopy is effective in diagnosing patients with suspected CD undetected by conventional diagnostic methods. It can be used to detect early lesions in the small bowel of patients with CD.

The effect of folic acid on the development of stomach and other gastrointestinal cancers.

OBJECTIVE: To evaluate the roles of folic acid and beta-carotene in the chemoprevention of gastric and other gastrointestinal (GI) cancers. METHODS: In a randomized, double-blind, placebo-controlled trial, a total of 216 patients with atrophic gastritis were randomly assigned to one of the four groups: (1) folate (FA, 20 mg per day plus vitamin B(12) 1 mg, intramuscularly, per month for one year, then 20 mg two times a week plus 1 mg per three months for the next year); (2) natural beta-carotene (N-betaC, 30 mg per day for first year, then 30 mg two times a week for the next); (3) synthetic beta-carotene (S-betaC, administered as in N-betaC); and (4) placebo. Follow-ups continued from 1994 to 2001. RESULTS: A total of 7 new cases of gastrointestinal cancers were diagnosed with 3 stomach, 1 colon and 1 esophageal cancers occurring in the placebo group; 1 stomach cancer in both of the N-betaC and S-betaC groups, and no cancer occurring in FA group. In terms of GI cancers, there was a significant reduction in the FA group, compared with the placebo group (P = 0.04). A similar trend was observed in both N-betaC and S-betaC groups (P = 0.07 - 0.08). Taken together, the three intervention groups displayed a highly significant decrease in occurrence (P = 0.004, vs placebo), and a lower risk for GI cancers (OR = 0.12; 95% confidence interval, 0.03 - 0.51). For development of gastric cancer, any one of the three active-treated groups did not reach statistically significant reduction. The FA group showed obvious improvement of the gastric mucosal lesions with more patients displaying lesions reversed or stable atrophy and inflammation (P = 0.04), reversed intestinal metaplasia (P = 0.06) at the end of follow-up, and reversed displasia (P = 0.017) at 12 months. Two cases of false jaundice were found in beta-carotene groups with no influence on administration, and no side-effects were reported in FA group. CONCLUSIONS: This trial revealed the interventional effect of folic acid on the development of GI cancers, a similar effect of beta-carotene was also detected. Also, folic acid may be of use to treat atrophic gastritis by preventing or reversing the precancerous lesions.