Petrosal Anatomy of the Paleocene Eutherian Mammal Deltatherium fundaminis (Cope, 1881)

We describe the tympanic anatomy of the petrosal of Deltatherium fundaminis, an enigmatic Paleocene mammal based on cranial specimens recovered from New Mexico, U.S.A. Although the ear region of Deltatherium has previously been described, there has not been a comprehensive, well-illustrated contribution using current anatomical terminology. The dental and cranial anatomy of Deltatherium is a chimera, with morphological similarities to both ‘condylarth’ and ‘cimolestan’ taxa. As such, the phylogenetic relationships of this taxon have remained elusive since its discovery, and it has variably been associated with Arctocyonidae, Pantodonta and Tillodontia. The petrosal of Deltatherium is anteriorly bordered by an open space comprising a contiguous carotid opening and pyriform fenestra. The promontorium features both a small rostral tympanic process and small epitympanic wing but lacks well-marked sulci. A large ventral facing external aperture of the canaliculus cochleae is present and bordered posteriorly by a well-developed caudal tympanic process. The hiatus Fallopii opens on the ventral surface of the petrosal. The tegmen tympani is mediolaterally broad and anteriorly expanded, and its anterior margin is perforated by a foramen for the ramus superior of the stapedial artery. The tympanohyal is small but approximates the caudal tympanic process to nearly enclose the stylomastoid notch. The mastoid is widely exposed on the basicranium and bears an enlarged mastoid process, separate from the paraoccipital process. These new observations provide novel anatomical data corroborating previous hypotheses regarding the plesiomorphic eutherian condition but also reveal subtle differences among Paleocene eutherians that have the potential to help inform the phylogeny of Deltatherium.

Safety of the application of Rigidfix cross-pin system via different tibial tunnels for tibial fixation during anterior cruciate ligament reconstruction

Background We investigate the safety of the application of the Rigidfix cross-pin system via different tibial tunnels in the tibial fixation during anterior cruciate ligament (ACL) reconstruction. Methods Five adult fresh cadaver knees were fixed with the Rigidfix cross-pins in the tibial fixation site during ACL reconstruction. Two different tibial tunnel groups were established: in group A, the tunnel external aperture was placed at the 25° angle of coronal section; in group B, the tunnel external aperture was placed at the 45° angle of coronal section. The guide was placed at the plane 0.5 mm below articular facet through the tibial tunnel, with three rotation positions set at 0°, 30°, and 60° slopes. The incidences of iatrogenic injuries at tibial plateau cartilage (TPC), medial collateral ligament (MCL), and patellar tendon in three different slope angles were calculated in groups A and B and the results were analyzed by using chi square test. Results The iatrogenic injuries at MCL, TPC, and patellar tendon could occur after the Rigidfix cross-pin system was placed 5 mm below tibial plateau cartilage for ACL reconstruction. The incidences of TPC injury (χ2 = 5.662, P = 0.017) and MCL injury (P = 0.048, Fisher exact probability method) were significantly lower in group A than in group B. However, the incidence of patellar tendon injury showed no significant difference between these two groups (χ2 = 0.120, P = 0.729). Conclusions When the Rigidfix cross-pin system is used for ACL reconstruction at the tibial fixation site, the external aperture of tibial tunnel should not be placed at the excessively posterosuperior site, to avoid MCL and TPC injuries.

Miniinvasive method of treatment of the duodenal sutures insufficiency

Objective. To improve the results of treatment in patients with insufficiency of duodenal sutures. Materials and metods. Retrospective and prospective investigation was accomplished on 17 patients, suffering insufficiency of sutures, injuries and fistulas of duodenum, who were admitted for treatment into Shalimov National Institute of Surgery and Transplantology during 2010-2020 yrs. In all the patients a complex examination, including a general clinical one, special laboratory and instrumental methods of investigation, was conducted. Results. Miniinvasive endoscopic method for the treatment of the duodenal sutures insufficiency was elaborated with a patent obtaining, which consists of endoscopic placement of a covered nitinol self-expanding stent into the defect zone. In presence of the complication, constituting a duodenal fistula, there was proposed to place a covered nitinol self-expanding stent into the defect zone together with vacuum-therapy from the side of the fistula external aperture. Due to application of the treatment method elaborated, it have become possible to reduce the morbidities quantity and to shorten the patients’ stationary stay by 36% - from (38.1 ± 4.16) to (25.4 ± 3.7) bed-days (p < 0.05). General mortality in the investigated group have constituted 9%, what was in two times lower, than the mortality index in a control group - 16%. Conclusion. The method, investigated by us, have constituted a combined approach with endoscopic placement of a self-expanding stent into the defect zone together with vacuum therapy from the external aperture of fistula, promoting improvement of the treatment results of the duodenal sutures insufficiency, accompanied by shortening of the patients’ stationary stay and reduction of morbidity and mortality.

Um Novo Espécime do Gênero Octodontobradys (Orophodontidae, Octodontobradyinae) do Mioceno Superior/Plioceno da Amazônia Sul-Ocidental, Brasil

This study presents an almost complete mandible of Octodontobradys sp. from the late Miocene-Pliocene of the Solimões Formation from a locality on the border between Brazil and Bolivia, in southwestern Amazonia. The two almost complete mandibular rami, together with fragments of fossils from other taxa, were found on the left bank of the Abunã River, upriver from the town of Plácido de Castro, in the Brazilian state of Acre. The form of the symphyseal region of the mandible, and the elongated and bilobated outline of the alveoli of the m2-3-4 molariforms place the specimen clearly in the genus Octodontobradys. However, the new specimen differs from O. puruensis in (a) the anterior position of the posterior external aperture of the mandibular canal, and (b) the wider and more anteriorly inclined symphyseal region. The mandible described here represents the first specimen of the genus Octodontobradys found outside of the holotype locality, Talismã, in the Brazilian state of Amazonas and enabled us to emend the diagnoses of Subfamily Octodontobradyinae.

Triceratium moreirae sp. nov. and Triceratium dubium (Triceratiaceae - Bacillariophyta) from estuarine environments of Southern Brazil, with comments on the genus Triceratium C. G. Ehrenberg

A new species of Triceratiaceae is described for estuarine environments of Southern Brazil. The valve of Triceratium moreirae sp. nov. is triangular with elevations bearing ocellus and a rimoportula in their basis. The valvar surface has robust pseudoloculi, circular to polygonal, each one confining a group of areolae arranged in a typical pattern. A central larger areola is surrounded by 5-8 smaller areolae, and they are poroidal with domed cribra. A septum emerges from the valvocopula, having the base reinforced by ribs and the margins folded to the innerside of the valve. The new species is compared to the closely related diatom Triceratium dubium, which has the same pattern of areolar disposition, formation of septum and pseudoloculi. The main diferences in relation to T. moreirae are: rimoportulae intercalated to ocelli and with a characteristic morphology (spinules on the edge of the external aperture), and more elongated elevations with a constriction. Some criteria used for the classification of categories into the Triceratiaceae are also discussed, and we propose that the type of areola (poroidal with cribra) be included in the circumscription of Triceratium.