Microdeletion 4q21 syndrome has been described in about a dozen patients with deletions ranging from 3.2 to 15.1 MB with similar features including the distinctive facial characteristics of broad forehead, hypertelorism, and prominent front teeth, with severe growth delay, developmental delay, and neonatal hypotonia. A 1.37 MB minimal critical region has been described that accounts for this shared phenotype and includes five known genes: PRKG2, RASGEF1B, HNRNPD, HNRPDL, and ENOPH1. We report on two new patients found through single nucleotide polymorphism (SNP) microarray testing that expand the reported phenotype. Patient 1 has a novel deletion of 2.0 MB, the smallest reported deletion, which involves only a partial deletion of the minimal critical region, including the genes HNRNPD, HNRPDL, and ENOPH1. She shares much of the typical phenotype including moderate developmental delay, unusual facial features, small hands and feet, but not any growth delay or neonatal hypotonia. This patient allows further genotype-phenotype correlation of the genes in the minimal critical region, and supports that heterozygous loss of PRKG2 leads to the growth delay. Patient 2 has a novel 3.4 MB deletion that includes the entire critical region, and has typical features, but also presented with cleft palate and Pierre Robin sequence, which have not been previously described. A gene reported to be associated with inherited cleft palate, SCD5, is in the deleted region in this patient, which suggests it may be playing a role in palate formation. Taken together, these patients allow for an expansion of the microdeletion 4q21 syndrome and provide candidate genes for particular features of the phenotype.

A family of precisely defined amphiphilic polyethylene-g-poly(ethylene glycol) copolymers has been synthesized using ADMET polycondensation chemistry. Altering the graft distribution and graft end group controls the morphology of the material:  the polymers can be either semicrystalline or rendered completely amorphous. The precise monomer structures have been confirmed by 1H and 13C NMR, high-resolution mass spectrometry, and elemental analysis; the corresponding polymer structures have been confirmed by 1H and 13C NMR and FTIR. Melting temperatures can be controlled over a 60 °C range and glass transition temperature over 40 °C. Melting temperatures are incident with n-paraffin molecules having lengths similar to the static methylene sequence length between PEG branches. The observed thermal data are attributed to the crystallization of the polyethylene backbone, resulting in the exclusion of the PEG branches from the crystal, a result confirmed by X-ray diffraction.

Osteochondrosis is a common developmental abnormality affecting the subchondral bone of immature, large breed dogs. The purpose of this retrospective study was to describe CT lesions detected in scapulohumeral joints of 32 immature dogs undergoing CT for thoracic limb lameness. Eight dogs (14 scapulohumeral joints) had arthroscopy following imaging. Thirteen dogs (19 scapulohumeral joints) were found to have CT lesions, including 10 dogs (16 scapulohumeral joints) with subchondral bone lesions and 3 dogs with enthesopathy of the supraspinatus tendon. In one dog, subchondral bone lesions appeared as large oval defects within the mid-aspect of the glenoid cavities, bilaterally. These lesions resembled osseous cyst-like lesions commonly identified in the horse. This is the first report of such a presentation of a subchondral bone lesion in the glenoid cavity of a dog. In all dogs, small, focal, round or linear lucent defects were visible within the cortical bone at the junction of the greater tubercle and intertubercular groove. These structures were thought to represent vascular channels. Findings from this study support the use of CT as an adjunct modality for the identification and characterization of scapulohumeral subchondral bone lesions in immature dogs with thoracic limb lameness.

A 6 yr old male Yorkshire terrier was presented for an ~6 yr history of progressive cough and dyspnea. Thoracic radiographs revealed a 6 cm diameter mass within the right caudal thorax. Thoracic ultrasound identified an intrathoracic mass ultrasonographically consistent with liver tissue and a chronic diaphragmatic hernia was suspected. Exploratory laparotomy was performed, but no evidence of a diaphragmatic hernia was identified. Thoracic exploration identified abnormal lung parenchyma. The accessory lung lobe was removed using a stapling devise near its base. The consolidated mass had the gross appearance of liver and was histologically identified as ectopic hepatic tissue. Ectopic hepatic tissue, unlike ectopic splenic and pancreatic tissue, is rare and generally has a subdiaphragmatic distribution. This solitary case report demonstrates that ectopic intrathoracic hepatic tissue should be considered a differential diagnosis for a caudal mediastinal mass.