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.

Inflammatory gastrointestinal disease presenting as genitourinary disease.

Chronic inflammatory bowel disease, diverticulitis, and appendicitis may be complicated by genitourinary tract problems. Patients with these diseases occasionally present with a genitourinary problem as an initial complaint prior to diagnosis of the underlying primary bowel disease. The correct diagnosis in these difficult cases will be arrived at sooner if the genitourinary manifestations of inflammatory diseases of the bowel are actively considered.

Congenital and acquired lung hernias.

Lung hernia is defined as a protrusion of lung parenchyma beyond the confines of the musculoskeletal thorax. Lung hernias can be classified according to location (i.e., cervical, thoracic, or diaphragmatic) and etiology. Approximately 80% of reported cases of lung hernia are acquired, usually related to trauma or surgery. Symptoms are few, infrequent, and vague. A painless, local, and inconstant bulging is evident on physical examination. The diagnosis of a lung herniation is accomplished using chest radiographs in the most cases. Surgery is usually reserved for large hernias or incarcerated hernias.

Computed tomography in traumatic defects of the diaphragm.

Two patients with traumatic diaphragmatic defects visible on computed tomography are presented. The diagnosis was delayed for several years in both patients. The diagnosis of these acquired diaphragmatic defects is often difficult. Computed tomography can lead to earlier diagnosis by demonstrating the defect in some patients when radiographic studies are not diagnostic.

Periportal tracking in pediatric blunt abdominal trauma. Correlation with liver enzymes and liver injury.

This is a retrospective study of the computed tomography (CT) examinations and medical records of 243 consecutive pediatric patients sent for CT studies after blunt abdominal trauma. The purpose of the study was to determine the frequency and significance of periportal tracking identified by CT, and correlate this finding with liver enzyme levels and liver injury. Periportal tracking (PPT) was divided into four grades (0-3) depending upon the distribution of decreased attenuation adjacent to the portal vessels. Circumferential PPT extending to the periphery of the liver (grade 3) was found in 20/243 children. They had a higher incidence of liver parenchymal injury seen on CT 20% versus 0.5% in combined PPT grades 0-2. Sixteen children with grade 3 PPT and no liver injury had significantly elevated liver enzymes as compared to children with combined 0-2 grade PPT. Eleven of the 20 children with grade 3 PPT had no other CT evidence of intraabdominal injury and none of these patients developed intraabdominal hemorrhage. Thus, grade 3 periportal tracking as an isolated abnormality did not indicate a clinically significant liver injury in any patient.

Coexistent adenocarcinoma and microcystic adenoma of the pancreas.

A case with coexistent pancreatic adenocarcinoma and microcystic adenoma is presented. These diagnoses were suspected on the basis of their computed tomography (CT) appearances and confirmed with CT-guided fine-needle aspiration.

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.

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.

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.

Longitudinal tibial stress fracture.

Fatigue-type stress fractures occur following repetitive loading of normal bone. These occur frequently in the tibia, although vertical orientation to the fracture is much less common than transverse orientation. Without a convincing history of new or accelerated muscular activity, imaging can be difficult to interpret and evaluation may require more than one imaging modality to exclude other diagnostic considerations, including neoplasm and osteomyelitis.