Molecular systematics and biogeographic history of the African climbing-mouse complex (Dendromus).

Climbing mice in the genus Dendromus (sensu lato) are widely distributed in Africa, south of the Saharan Desert. The 17 currently recognized species in the genus range from widespread taxa to single-mountain endemics, and there is considerable variation across species with respect to habitats occupied. These habitats range from arid grasslands and savannahs to sub-alpine and alpine vegetation. Using the most comprehensive geographic and genetic survey to date and after reviewing many type specimens, we assess the systematics and biogeography of Dendromus. Given the structure of our molecular phylogenetic hypotheses, in which we recover six major clades, we propose the recognition of three genera within the Dendromus group (sensu lato): in addition to Dendromus (26 lineages), we suggest the retention of Megadendromus (monotypic) and the resurrection of the genus Poemys (six lineages). From our model-based molecular phylogenetic results and morphological comparisons, we suggest that six formerly synonymized taxa should be resurrected, and we highlight 14 previously undescribed lineages. We also constructed time-calibrations on our phylogeny, and performed ancestral area reconstructions using BioGeoBEARS. Based on fossil evidence, Dendromus appears to have had a widespread African distribution dating back to the Late Miocene (8-10 Ma), and our basal ancestral area reconstruction (Ethiopians Highlands + Eastern African Mountains + Zambezian region) supports this. Divergence of the six major clades we recover (Poemys, Megadendromus and four within Dendromus) occurred prior to or at the Miocene-Pliocene boundary 5.3 Ma. Biogeographically, Megadendromus is restricted to the Ethiopian Highlands. The ancestral area for Poemys is reconstructed as the Zambezian region, with species distributions ranging from South Africa to Western Africa. The ancestral area for Dendromus is reconstructed as the Ethiopian Highlands, with the ancestral areas of the four major clades being reconstructed as Ethiopian Highlands, Albertine Rift, South Africa or Western Africa. None of the four Dendromus clades are reciprocally monophyletic with respect to distributional area.

Pancreaticothoracic fistulas: imaging findings in five patients.

BACKGROUND: Pancreaticothoracic fistulas are a rare complication of chronic pancreatitis. This study evaluated the imaging findings in patients with pancreaticothoracic fistulas. METHODS: We retrospectively reviewed the medical records and radiographic images in five patients with pancreaticothoracic fistulas diagnosed at our institution during the previous 6 years. Data from radiography, endoscopic retrograde cholangiopancreatography (ERCP), computed tomography (CT), magnetic resonance cholangiopancreatography, and drainage catheter studies were evaluated. RESULTS: Persistent pleural effusions were present on the radiographs of all patients. ERCP was performed in three patients. Contrast material was injected into drainage catheters placed in a pancreatic pseudocyst in one patient and a pancreatic abscess in another patient. Pancreaticothoracic fistulas were demonstrated on all of these studies. One patient had a CT study immediately after ERCP and another patient had a CT study immediately after contrast material was injected through a drainage catheter placed percutaneously in a pseudocyst. CT demonstrated the full extent of the pancreaticothoracic fistula in both patients. CONCLUSION: Pancreaticothoracic fistulas are rare and may require multiple imaging modalities to establish a diagnosis.

Fibrous dysplasia complicated by aneurysmal bone cyst formation affecting multiple cervical vertebrae.

Fibrous dysplasia is a well-known benign dysplastic process of bone. However, fibrous dysplasia is very uncommon in the spine. Further, to our knowledge, coexistence of fibrous dysplasia and aneurysmal bone cyst in the spine has not been reported. This manuscript presents a patient who had both processes involving the cervical spine.

Radiographic herald lesion of the urinary bladder: pictorial essay.

At cystoscopy a focal mucosal abnormality may be indicative of a pathological process extrinsic to the urinary bladder and has been termed 'the herald lesion'. The aim of the present pictorial essay was to describe the radiographic counterpart to this cystoscopic finding. Radiographic herald lesions are shown in patients with extravesical inflammatory (Crohn's disease, colonic diverticulitis and pelvic inflammatory disease) and neoplastic (colon carcinoma) processes, and urinary tract complications of these conditions are described and illustrated.

Computed tomographic imaging of the foot and ankle. Developmental and congenital anomalies.

Computed tomography is a primary imaging technique for evaluating congenital and developmental anomalies of the foot and ankle. Other imaging modalities have special capabilities, but computed tomography is a fast, safe, and effective method of assessing the anatomy. To demonstrate this point, the authors present and discuss imaging findings of common anomalies of the foot and ankle.

Traumatic pseudoaneurysm of the brachial artery.

Detection and treatment of vascular injuries in extremity and pelvic trauma can be challenging. Angiography, while no longer routinely used in asymptomatic patients, is still a primary means of diagnosis. Appropriate patient selection based on physical examination, along with other less invasive imaging modalities, can decrease the need for angiography while still detecting the vast majority of clinically significant injuries. Angiography also plays a definitive therapeutic role in most cases of significant hemorrhage in the pelvis through precise identification and selective embolization of bleeding vessels.

Radiologic case study. Fractures of the foot masquerading as ankle injuries.

An ankle radiographic series frequently is obtained when a patient presents with an acute ankle and foot injury. Although many fractures are confined to the ankle and are readily apparent, fractures of the foot can mimic ankle injuries. It is important to differentiate these fractures of the foot from the more common ankle sprain. Most ankle sprains are treated with ice, compression, and elevation, followed by range-of-motion exercises and progressive weight bearing as tolerated. When foot fractures are not identified, however, lack of appropriate treatment can result in late complications. Concentration on key areas as described here will reduce the incidence of missed fractures of the foot in these patients.