Arthroscopically assisted removal of intraosseous ganglion cysts of the distal tibia

Intraosseous ganglia of the distal tibia are rare. We evaluated the feasibility of surgically treating these lesions with an arthroscopically assisted technique. Five patients with symptomatic distal tibial ganglia underwent surgical curettage and excision with this technique. All patients underwent débridement of the chondral lesion and hypertrophied synovial lining when present, probing of the portal to the ganglion, and subsequently thorough curettage with bone grafting performed through a cortical window made from a separate small incision. Biopsy confirmed the diagnosis in all patients. All patients had eventual relief of symptoms with good integration of bone graft at final followup. There were no recurrences at a minimum followup of 19 months (mean, 38.6 months; range, 19-69 months). Mean time for return to full function was 15.4 weeks (range, 8-17 weeks). There were no intraoperative or postoperative complications. The mean American Orthopaedic Foot and Ankle Society scores increased from 73 points (range, 67-77 points) preoperatively to 94 points (range, 90-100 points) postoperatively. Arthroscopically assisted surgical treatment of ganglia of the distal tibia in the appropriate patient is a reasonably simple technique that relieves symptoms and helps the patient to regain normal gait and full function with no recurrence (in our small series). LEVEL OF EVIDENCE: Level IV, case series. See Guidelines for Authors for a complete description of levels of evidence.

Selective removal of anomeric O-acetate groups in carbohydrates using HCl04-Si02-tr

A convenient methodology has been developed for the selective removal of the anomeric acyl group of carbohydrate derivatives using HCI04-Si02 under acidic reaction conditions. Anomeric benzoyl groups can also be removed selectively following similar reaction conditions. The yields were excellent in all cases.

Ctp1CtIP and Rad32Mre11 nuclease activity are required for Rec12Spo11 removal, but Rec12Spo11 removal is dispensable for other MRN-dependent meiotic functions

The evolutionarily conserved Mre11/Rad50/Nbs1 (MRN) complex is involved in various aspects of meiosis. Whereas available evidence suggests that the Mre11 nuclease activity might be responsible for Spo11 removal in Saccharomyces cerevisiae, this has not been confirmed experimentally. This study demonstrates for the first time that Mre11 (Schizosaccharomyces pombe Rad32(Mre11)) nuclease activity is required for the removal of Rec12(Spo11). Furthermore, we show that the CtIP homologue Ctp1 is required for Rec12(Spo11) removal, confirming functional conservation between Ctp1(CtIP) and the more distantly related Sae2 protein from Saccharomyces cerevisiae. Finally, we show that the MRN complex is required for meiotic recombination, chromatin remodeling at the ade6-M26 recombination hot spot, and formation of linear elements (which are the equivalent of the synaptonemal complex found in other eukaryotes) but that all of these functions are proficient in a rad50S mutant, which is deficient for Rec12(Spo11) removal. These observations suggest that the conserved role of the MRN complex in these meiotic functions is independent of Rec12(Spo11) removal.

Ctp1 and the MRN-complex are required for endonucleolytic Rec12 removal with release of a single class of oligonucleotides in fission yeast

DNA double-strand breaks (DSBs) are formed during meiosis by the action of the topoisomerase-like Spo11/Rec12 protein, which remains covalently bound to the 5' ends of the broken DNA. Spo11/Rec12 removal is required for resection and initiation of strand invasion for DSB repair. It was previously shown that budding yeast Spo11, the homolog of fission yeast Rec12, is removed from DNA by endonucleolytic cleavage. The release of two Spo11 bound oligonucleotide classes, heterogeneous in length, led to the conjecture of asymmetric cleavage. In fission yeast, we found only one class of oligonucleotides bound to Rec12 ranging in length from 17 to 27 nucleotides. Ctp1, Rad50, and the nuclease activity of Rad32, the fission yeast homolog of Mre11, are required for endonucleolytic Rec12 removal. Further, we detected no Rec12 removal in a rad50S mutant. However, strains with additional loss of components localizing to the linear elements, Hop1 or Mek1, showed some Rec12 removal, a restoration depending on Ctp1 and Rad32 nuclease activity. But, deletion of hop1 or mek1 did not suppress the phenotypes of ctp1Delta and the nuclease dead mutant (rad32-D65N). We discuss what consequences for subsequent repair a single class of Rec12-oligonucleotides may have during meiotic recombination in fission yeast in comparison to two classes of Spo11-oligonucleotides in budding yeast. Furthermore, we hypothesize on the participation of Hop1 and Mek1 in Rec12 removal.

Right ventricular rupture after lateral thoracotomy for removal of rib-associated telangiectatic osteosarcoma in a dog

OBJECTIVE: To describe a case of a focal right ventricular rupture following removal of a rib-associated telangiectatic osteosarcoma (TOS) in a dog. CASE SUMMARY: A 2-year-old spayed female mixed-breed dog, weighing 20 kg, was presented in compensated hypovolemic shock due to active bleeding into the thoracic cavity. The dog was stabilized with appropriate fluid administration. Subsequent computed tomographic examination revealed a large mineralized mass originating from the body of a rib and displacing the heart. Two days after surgical removal of this mass, focal right ventricular rupture occurred and the dog died. The mass was later identified as a TOS. NEW OR UNIQUE INFORMATION PROVIDED: Although hemothorax secondary to TOS has been described previously, this report describes for the first time, spontaneous focal right ventricular rupture as a rare complication of thoracotomy and rib resection for the removal of a rib-associated, intrathoracic TOS.

Oesophageal and gastric endoscopic foreign body removal: complications and follow-up of 102 dogs

OBJECTIVES: To assess complication rate, risk factors for complications and outcome in dogs with oesophageal and gastric endoscopic foreign body (FB) removal. METHODS: Medical records of 102 dogs undergoing endoscopic removal of oesophageal and/or gastric FBs from March 2001 to November 2006 were retrospectively reviewed. All owners were contacted by telephone to provide follow-up information. RESULTS: West Highland white terriers, Yorkshire terriers and Bernese mountain dogs were over-represented compared to the hospital population. Endoscopy alone was successful in 92/102 dogs (90.2 per cent), whereas gastrotomy (but no oesophagotomy) was required in 10 dogs (9.8 per cent). Complications in 13/102 dogs (12.7 per cent) were perforation (8), oesophageal stricture (1), oesophageal diverticula (1), perioesophageal abscess (1), pneumothorax and pleural effusion (1) and respiratory arrest (1). Six dogs (all weighing <10 kg) had complications resulting in death or euthanasia. Bone FBs, bodyweight of less than 10 kg, and oesophageal or gastric FB in place for more than three days were significant risk factors for complications. Of the dogs available for follow-up (75/96), 92 per cent had no complications after discharge. CLINICAL SIGNIFICANCE: Endoscopic FB removal is associated with a low overall complication rate with bone FBs and bodyweight of less than 10 kg as significant risk factors.

A novel cryo-mechanical approach for the removal of blocked nonretrievable implant components

The removal of nonretrievable implant components represents a challenge in implant dentistry. The mechanical approach involves the risk of damaging the implant connection or the bone-to-implant interface. This case report describes a cryo-mechanical approach for the safe removal of a nonretrievable implant component. A patient had an implant surgically placed in a private practice. When the patient returned to the restorative dentist to make a definitive impression, the healing abutment could not be loosened. The patient was referred to the Division of Fixed Prosthodontics (University of Bern, Switzerland), where the stripped screw hole was enlarged with a special drill from a service kit of the implant provider. Although an extraction bolt was screwed into the opening and the torque ratchet was activated, the healing abutment would not loosen. A novel approach was attempted whereby the healing abutment was cooled with dry ice (CO2). The cooling effect seemingly caused shrinkage of the healing abutment and a reduction of the connection forces between the implant and the nonretrievable component. The approach of creating an access hole for the application of reverse torque via the extraction bolt in combination with the thermal effect led to the successful removal of the blocked component. Neither the implant connection nor the bone-to-implant interface was damaged. The combined cryo-mechanical procedure allowed the implant to be successfully restored.

Subordinate removal affects parental investment, but not offspring survival in a cooperative cichlid

Summary Subordinates in cooperative breeding systems may provide help to dominant pairs, who can benefit by either an increased total investment in their current brood or a reduced personal contribution to this investment. In the social cichlid Julidochromis ornatus, one large male subordinate generally spends 90% of his time in close proximity to the breeding shelter, whereas the dominants only spend 50% of their time close to the shelter. We experimentally removed the large subordinate for 30 days (approximating one breeding cycle) to study the investment strategies of dominants and the effects on offspring survival, while accounting for subordinate immigration. Experimental groups were compared with control groups, from which subordinates were also caught but not removed. On day one following removal, we tested whether dominants overcompensated, fully compensated or undercompensated for absence of the subordinate on several parental behaviours. Moreover, we tested whether the pairs' potential compensatory behaviour remained high seven days following large subordinate removal. One day following removal, dominants increased their time spent in the territory and their frequency of breeding shelter visits and defence, compared with the pre-removal phase and control groups. The dominant pair overcompensated for the loss of subordinate help in their breeding shelter visits, fully compensated in defence and undercompensated their time spent in the territory. Seven days after large subordinate removal, behavioural differences between treatments had disappeared. However, when distinguishing between groups with or without a new immigrant subordinate, dominant pairs only diminished investment in the presence of an immigrant, suggesting a compensatory role of the large subordinate. Finally, survival of juvenile group members was not affected by the treatment. Our experiments indicate that the presence of a large subordinate does not increase the dominant pairs' current reproductive success, but instead allows them to reduce their personal contribution to investment in the current brood. In addition, we illustrate that dominants may show strikingly different compensatory responses depending on the type of behaviour and emphasize the importance of immigrant subordinates to relieve dominants from costly compensatory responses in cooperative breeding systems.