This two-part study reviews data from a recently developed colony of New Zealand white rabbits with familial, nonsyndromic unilateral coronal suture synostosis, and this second part presents neuropathological findings and age-related changes in intracranial volume (ICV) and intracranial pressure (ICP) in 106 normal rabbits and 56 craniosynostotic rabbits from this colony. Brain morphology and anteroposterior length were described in 44 rabbit fetuses and perinates (27 normal; 17 synostosed). Middle meningeal artery patterns were qualitatively assessed from 2-D PCC MRI VENC scans and endocranial tracings from 15, 126-day-old rabbits (8 normal, 7 rabbits with unicoronal synostosis). Brain metabolism was evaluated by assessing 18F-FDG uptake with high-resolution PET scanning in 7, 25-day-old rabbits (3 normal, 4 with unicoronal or bicoronal synostosis). Intracranial contents and ICV were assessed using 3-D CT scanning of the skulls of 30 rabbits (20 normal,10 with unicoronal synostosis) at 42 and 126 days of age. Serial ICP data were collected from 66 rabbits (49 normal; 17 with unicoronal synostosis) at 25 and 42 days of age. ICP was assessed in the epidural space using a Codman NeuroMonitor microsensor transducer. Results revealed that cerebral cortex morphology was similar between normal and synostosed fetuses around the time of synostosis. Significantly (P<0.05) decreased A-P cerebral hemisphere growth rates and asymmetrical cortical remodeling were noted with increasing age in synostotic rabbits. In addition, rabbits with unicoronal suture synostosis exhibited asymmetrical middle meningeal artery patterns, decreased and asymmetrical brain metabolism, a "beaten-copper" intracranial appearance, significantly (P<0.05) decreased ICV, and significantly (P<0.01) elevated ICP compared with normal control rabbits. The advantages and disadvantages of these rabbits as a model for human familial, nonsyndromic unicoronal suture synostosis are discussed, especially in light of recent clinical neuropathological, ICV, and ICP findings recorded in human craniosynostotic studies.

Mesenchymal stem cells remain of great interest in regenerative medicine due to their ability to home to sites of injury, differentiate into a variety of relevant lineages, and modulate inflammation and angiogenesis through paracrine activity. Many studies have found that despite the great promise of MSC therapy, cell survival upon implant is highly limited and greatly reduces the therapeutic utility of MSCs. The matrikine Tenascin C, a protein expressed often at the edges of a healing wound, contains unique EGF-like repeats that are able to bind EGFR at low affinity and induce downstream pro-survival signaling without inducing receptor internalization. In this study, we utilized Tenascin C in a collagen/GAG-based polymer (Tpolymer) for skin wound healing, incorporating human MSCs into the polymer prior to application to mouse punch biopsy wound beds. We found that the TPolymer was able to promote MSC survival out to 21 days in vivo, leading to associated improvements in wound healing such as dermal maturation and collagen content. This was most marked in a model of hypertrophic scarring, in which the scar formation was limited. This approach also reduced the inflammatory response in the wound bed, limiting CD3e+ cell invasion by approximately 50% in the early wound healing process, while increasing the numbers of endothelial cells during the first week of wound healing as well. Ultimately, this matrikine-based approach to improving MSC survival may be of great use across a variety of cell therapies utilizing matrices as delivery vehicles for cells.

Poswillo has stated, "The more severe anomalies of the calvaria, such as plagiocephaly, Crouzon [syndrome], and Apert syndrome still defy explanation, in the absence of an appropriate animal system to study" (p. 207). This two-part study reviews data from a recently developed colony of New Zealand white rabbits with familial, nonsyndromic unilateral coronal suture synostosis. Part 1 presents pathological findings and compensatory sutural growth data from 109 normal rabbits and 82 craniosynostotic rabbits from this colony. Synostotic foci, onset, and progression were described in the calvariae from 102 staged (fetal days 21, 25, 27, 33; term = 30 days) fetuses (39 normal, 63 synostosed). Calvarial suture growth patterns from 10 to 126 days of age were assessed from serial radiographs obtained from 89 rabbits (70 normal rabbits and 19 rabbits with unicoronal suture synostosis) with amalgam bone marker implants. Perinatal results revealed that by fetal day 25 the synostotic focal point in synostotic rabbits consistently originated from the endocortical surface of the calvaria in the middle of the coronal suture at a presumed high-tension, interdigitating zone. Histological analysis revealed hyperostotic osteogenic fronts on the affected side compared with the unaffected side. Postnatal sutural growth data revealed a predictable pattern of plagiocephaly (contralateral coronal sutures growing more than ipsilateral sutures and ipsilateral frontonasal and anterior lambdoidal sutures growing more than contralateral sutures), which resulted in early cranial vault deformities and a double "S" shape torquing towards the affected side. The advantages and disadvantages of these rabbits as a model for human familial, nonsyndromic unicoronal suture synostosis are discussed, especially in light of recent cytokine and genetic findings from human craniosynostotic studies.

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