Clonal reproduction with androgenesis and somatic recombination: the case of the ant Cardiocondyla kagutsuchi.

In haplodiploid insects such as ants, male sexuals develop from unfertilised haploid eggs, while female sexuals and workers develop from fertilized diploid eggs. However, some ant species do not exchange their gene pool between sexes; both male and female sexuals are clonally produced, while workers are sexually produced. To date, three ant species, Wasmannia auropunctata, Vollenhovia emeryi, and Paratrechina longicornis, have been reported to reproduce using such reproductive systems. In this study, we reveal that in one lineage of the ant Cardiocondyla kagutsuchi, male and female sexuals are also clonally produced. In contrast to the abovementioned three species, the workers were not only sexually produced but had recombinant sequences in their nuclear internal transcribed spacer regions, although the recombinant sequences were not detected in male or female sexuals. These results suggest that the lineage likely possesses a mechanism to compensate for the reduction in genetic variation due to clonal reproduction with somatic recombination that occurs within the workers.

Double-balloon endoscopy-diagnosed multiple small intestinal ulcers in a Churg-Strauss syndrome patient.

Churg-Strauss syndrome (CSS) is a systemic vascular disorder characterized by severe bronchial asthma, hypereosinophilia, and allergic rhinitis. Small intestinal ulcers associated with CSS are a relatively rare manifestation that causes gastrointestinal bleeding. Multiple deep ulcers with an irregular shape are characteristic of small intestinal involvement of CSS. Video-capsule-endoscopy (VCE), double-balloon endoscopy (DBE) and Spirus assisted enteroscopy have been developed recently and enabled observation of the small intestine. In this case report, we have described a patient with CSS who had multiple deep ulcers in the jejunum detected by oral DBE. Since severe gastrointestinal (GI) involvement has been identified as an independent factor associated with poor outcome, the careful investigation of GI tract must be needed for CSS patients with GI symptoms. We describe the usefulness of DBE for diagnosis of small intestinal ulcers in patient with CSS.

Clinical utility of double-balloon enteroscopy for small intestinal bleeding.

Until the development of wireless capsule endoscopy (CE) and double-balloon enteroscopy (DBE), it was extremely difficult to examine the entire small intestine. To assess the usefulness of DBE for diagnosing suspected small intestinal bleeding, we retrospectively compared the diagnoses and treatments of cases before and after its introduction at one hospital. Between September 2003 and December 2005, 21 consecutive patients with suspected small intestinal bleeding underwent DBE at Tokai University Hospital (group A), and subsequently 2 were excluded from the study after being diagnosed with bleeding from a diverticulum and an angiodysplasia in the ascending colon, respectively. For comparison, inpatients who were negative for gastrointestinal bleeding on colonoscopy and gastroscopy between May 1998 and August 2003 were reviewed and 27 consecutive patients who had not undergone DBE were selected as the control group (group B). All patients had been diagnosed negative for a source of bleeding on more than one colonoscopy and gastroscopy. There were no significant differences between the two groups in terms of age, gender, history of blood transfusion, blood hemoglobin value on admission, or symptoms. The diagnostic yield of DBE in identifying the source of bleeding was 78.9%: six cases of small intestinal ulcers, five cases of angiodysplasia, two cases of hard submucosal tumor (SMT), one case of small pulsating SMT, and one case of small intestinal cancer. DBE was also used to successfully treat three cases of angiodysplasia with argon plasma coagulation. In the control group, conventional investigations, including enteroclysis, angiography, Meckel scan, scintigraphy with technetium-labeled red blood cells, and/or push enteroscopy, were performed in 88.9%, 29.6%, 29.6%, 55.6%, and 25.9%, respectively. The overall diagnostic yield of the conventional approaches was only 11.1% (P < 0.01), comprising a Meckel's diverticulum, a polyp, and an angiodysplasia. We conclude that DBE can be used to diagnose suspected small intestinal bleeding and to treat some cases, such as angiodysplasia.