Faculty Bibliography

Hereditary Inclusion Body Myopathy (HIBM) is a unique group of neuromuscular disorders characterized by adult onset and a typical muscle pathology. We have recently identified the gene encoding for a bifunctional enzyme, UDP-N-acetylglucosamine 2 epimerase/N-acetylmannosamine kinase (GNE), as the mutated gene in the prototype form of the disease presenting quadriceps sparing, particularly common in Middle Eastern Jews. Interestingly, we have identified the homozygous M712T Middle Eastern Jewish mutation also in two unrelated Middle Eastern Moslem families. We have also evaluated the involvement of GNE in several families from worldwide non-Jewish ethnic origins presenting symptoms similar to the Middle Eastern HIBM prototype. A total of 14 GNE mutations were identified (one nonsense and 13 missense), of which six are novel: an homozygous missense mutation in a consanguineous family from Italy and in a non consanguineous family from USA, and distinct compound heterozygotes in families from Germany, Italy, Ireland, Bahamas, USA and East India. This study brings to 17 the number of reported GNE mutations in quadriceps sparing myopathy, occurring either in the epimerase or the kinase domain of the enzyme. The mechanism leading to this unique phenotype still remains to be elucidated.

The potential widespread use of tissue-engineered matrices in soft-tissue reconstruction has been limited by the difficulty in fabricating and confirming a functional microcirculation. Acellular dermal matrix placed in a soft-tissue pocket acts as a scaffold to be incorporated by the host's fibrovascular tissue. A new method for noninvasive real-time observation of functional microvascular networks using orthogonal polarization spectral (OPS) imaging has recently been reported. Arterioles, venules, and capillaries can be directly visualized, and the movement of individual blood cells through them can be observed. The present study was performed to investigate the use of prefabricated acellular dermal matrix with an arteriovenous unit for the repair of abdominal muscle defects. OPS imaging was used to determine the presence of a functional microcirculation in the neovascularized matrix. In Sprague-Dawley rats, vascularized matrix was prefabricated by placing the superficial epigastric artery and vein on a 2-cm x 2-cm implant-type acellular dermal matrix in the thigh. Three weeks after implantation, the matrix-arteriovenous unit was elevated as an axial-type flap and a 2-cm x 2-cm full-thickness block of abdominal muscle immediately superior to the inguinal ligament was resected. Additional procedures were performed according to group: no repair (group 1, = 20); repair with nonvascularized acellular dermal matrix (group 2, = 20); repair with devascularized acellular dermal matrix (group 3, = 20); and repair with vascularized acellular dermal matrix (group 4, = 20). OPS imaging (field of view, 1 mm in diameter; scan depth range, 0.2 mm) was performed on both sides of each flap on a total of 10 random distal regions before and after pedicle transection in group 3 and with the pedicle preserved in group 4. Hernia rate and duration of survival were compared for 21 days. OPS imaging showed directional blood cell movement through the capillary network in all areas scanned in group 4. No microvascular perfusion was observed after pedicle transection in group 3. Hernia rates of 100, 80, 90, and 0 percent were seen in groups 1, 2, 3, and 4, respectively. Median survival times of 9, 11.5, 9, and 21 postoperative days were noted in groups 1, 2, 3, and 4, respectively. Histopathologic analysis with factor VIII revealed full-thickness infiltration of the matrix by endothelial cells, signifying newly formed blood vessels. Repair of abdominal muscle defects using vascularized acellular dermal matrix resulted in no hernia and survival of all animals for the duration of study. However, repairs using avascular or devascularized matrix resulted in significant rates of hernia and decreased survival. Acellular dermal matrix can be prefabricated into vascularized tissue using an arteriovenous unit and used successfully to repair abdominal muscle defects. OPS imaging allowed for high-contrast direct visualization of microcirculation in previously acellular tissue following prefabrication with an arteriovenous unit

Although it is known that systemic diseases such as diabetes result in impaired wound healing, the mechanism for this impairment is not understood. Because fibroblasts are essential for wound repair, we compared the in vitro behavior of fibroblasts cultured from diabetic, leptin receptor-deficient (db/db) mice with wild-type fibroblasts from mice of the same genetic background in processes important during tissue repair. Adult diabetic mouse fibroblast migration exhibited a 75% reduction in migration compared to normal fibroblasts (P < 0.001) and was not significantly stimulated by hypoxia (1% O(2)), whereas wild-type fibroblast migration was up-regulated nearly twofold in hypoxic conditions (P < 0.05). Diabetic fibroblasts produced twice the amount of pro-matrix metalloproteinase-9 as normal fibroblasts, as measured by both gelatin zymography and enzyme-linked immunosorbent assay (P < 0.05). Adult diabetic fibroblasts exhibited a sevenfold impairment in vascular endothelial growth factor (VEGF) production (4.5 +/- 1.3 pg/ml versus 34.8 +/- 3.3 pg/ml, P < 0.001) compared to wild-type fibroblasts. Moreover, wild-type fibroblast production of VEGF increased threefold in response to hypoxia, whereas diabetic fibroblast production of VEGF was not up-regulated in hypoxic conditions (P < 0.001). To address the question whether these differences resulted from chronic hyperglycemia or absence of the leptin receptor, fibroblasts were harvested from newborn db/db mice before the onset of diabetes (4 to 5 weeks old). These fibroblasts showed no impairments in VEGF production under basal or hypoxic conditions, confirming that the results from db/db fibroblasts in mature mice resulted from the diabetic state and were not because of alterations in the leptin-leptin receptor axis. Markers of cellular viability including proliferation and senescence were not significantly different between diabetic and wild-type fibroblasts. We conclude that, in vitro, diabetic fibroblasts show selective impairments in discrete cellular processes critical for tissue repair including cellular migration, VEGF production, and the response to hypoxia. The VEGF abnormalities developed concurrently with the onset of hyperglycemia and were not seen in normoglycemic, leptin receptor-deficient db/db mice. These observations support a role for fibroblast dysfunction in the impaired wound healing observed in human diabetics, and also suggest a mechanism for the poor clinical outcomes that occur after ischemic injury in diabetic patients

A joint urban planning and public health perspective is articulated here for use, in health impact assessment. Absent a blueprint for a coherent and supportive structure on which to test our thinking, we are bound to fall flat. Such a perspective is made necessary by the sheer number of people living in cities throughout the world, the need for explicit attention to land use and transportation systems as determinants of population health, and the dearth of useful indicators of the built environment for monitoring progress. If explicit attention is not paid to the overarching goals of equality and democracy, they have little if any chance of being realized in projects, programs, and policies that shape the built environment and therefore the public's health.

Placement of endosseous implants and inferior alveolar nerve transposition is a treatment option for patients with an edentulous posterior mandible with inadequate bone height superior to the inferior alveolar canal. Complications associated with these procedures include infection, prolonged neurosensory disturbances, and/or pathologic fracture. This report presents the surgical management of a patient with a mandible fracture after inferior alveolar nerve transposition with concurrent placement of two endosseous implants.