Searched for: school:SOM
Department/Unit:Cell Biology
Severe hyperglycemic hyperosmolar nonketotic coma in a nondiabetic patient receiving aripiprazole
Campanella, Lisa Marie; Lartey, Richard; Shih, Richard
Aripiprazole is commonly used as an atypical antipsychotic. It has been associated with abnormalities in glucose metabolism. Severe diabetic complications associated with its use occur rarely. We present a case of a patient without a history of diabetes mellitus who presented to the emergency department in severe hyperosmolar nonketotic coma while using aripiprazole
PMID: 18468728
ISSN: 1097-6760
CID: 129206
Fracture of fully coated echelon femoral stems in revision total hip arthroplasty [Case Report]
Landa, Joshua; Benke, Michael; Dayan, Alan; Pereira, Gavin; Di Cesare, Paul E
Three cases of fractured uncemented, fully porous Echelon femoral stems (Smith & Nephew, Memphis, Tenn) are examined. Fracture of these components, an uncommon complication of revision hip surgery, is thought to result from cantilever bending after distal bony ingrowth. The stems in these cases fractured at 11, 22, and 28 months after revision surgery. Risk factors include increased body weight, excessive activity, an undersized stem, varus alignment, inadequate proximal femoral bone stock, and metallurgic defects. Extraction can be difficult and is often accomplished with the use of multiple trephines or via tamping through a distal cortical window
PMID: 19159839
ISSN: 1532-8406
CID: 99134
Biodiversity conservation in local planning
Miller, James R; Groom, Martha; Hess, George R; Steelman, Toddi; Stokes, David L; Thompson, Jan; Bowman, Troy; Fricke, Laura; King, Brandon; Marquardt, Ryan
Local land-use policy is increasingly being recognized as fundamental to biodiversity conservation in the United States. Many planners and conservation scientists have called for broader use of planning and regulatory tools to support the conservation of biodiversity at local scales. Yet little is known about the pervasiveness of these practices. We conducted an on-line survey of county, municipal, and tribal planning directors (n =116) in 3 geographic regions of the United States: metropolitan Seattle, Washington; metropolitan Des Moines, Iowa; and the Research Triangle, North Carolina. Our objectives were to gauge the extent to which local planning departments address biodiversity conservation and to identify factors that facilitate or hinder conservation actions in local planning. We found that biodiversity conservation was seldom a major consideration in these departments. Staff time was mainly devoted to development mandates and little time was spent on biodiversity conservation. Regulations requiring conservation actions that might benefit biodiversity were uncommon, with the exception of rules governing water quality in all 3 regions and the protection of threatened and endangered species in the Seattle region. Planning tools that could enhance habitat conservation were used infrequently. Collaboration across jurisdictions was widespread, but rarely focused on conservation. Departments with a conservation specialist on staff tended to be associated with higher levels of conservation actions. Jurisdictions in the Seattle region also reported higher levels of conservation action, largely driven by state and federal mandates. Increased funding was most frequently cited as a factor that would facilitate greater consideration of biodiversity in local planning. There are numerous opportunities for conservation biologists to play a role in improving conservation planning at local scales
PMID: 19016822
ISSN: 1523-1739
CID: 94875
Endothelial caveolin-1 regulates pathologic angiogenesis in a mouse model of colitis
Chidlow, John H Jr; Greer, Joshua J M; Anthoni, Christoph; Bernatchez, Pascal; Fernandez-Hernando, Carlos; Bruce, Megan; Abdelbaqi, Maisoun; Shukla, Deepti; Granger, D Neil; Sessa, William C; Kevil, Christopher G
BACKGROUND & AIMS: Increased vascular density has been associated with progression of human inflammatory bowel diseases (IBDs) and animal models of colitis. Pathologic angiogenesis in chronically inflamed tissues is mediated by several factors that are regulated at specialized lipid rafts known as caveolae. Caveolin-1 (Cav-1), the major structural protein of caveolae in endothelial cells, is involved in the regulation of angiogenesis, so we investigated its role in experimental colitis. METHODS: Colitis was induced by administration of dextran sodium sulfate to wild-type and Cav-1(-/-) mice, as well as Cav-1(-/-) mice that overexpress Cav-1 only in the endothelium. Colon tissues were analyzed by histologic analyses. Leukocyte recruitment was analyzed by intravital microscopy; angiogenesis was evaluated by immunohistochemistry and in vivo disk assays. RESULTS: Cav-1 protein levels increased after the induction of colitis in wild-type mice. In Cav-1(-/-) mice or mice given a Cav-1 inhibitory peptide, the colitis histopathology scores, vascular densities, and levels of inflammatory infiltrates decreased significantly compared with controls. Lower levels of leukocyte and platelet rolling and adhesion colitis also were observed in Cav-1(-/-) mice and mice given a Cav-1 inhibitory peptide, compared with controls. Cav-1(-/-) mice that received transplants of wild-type bone marrow had a lower colitis score than wild-type mice. Data from mice that overexpress Cav-1 only in the endothelium indicated that endothelial Cav-1 is the critical regulator of colitis. Genetic deletion or pharmacologic inhibition of endothelial Cav-1 also significantly decreased vascular densities and angiogenesis scores, compared with controls. CONCLUSIONS: Endothelial Cav-1 mediates angiogenesis in experimental colitis. Modulation of Cav-1 could provide a novel therapeutic target for IBD
PMCID:3667411
PMID: 19111727
ISSN: 1528-0012
CID: 103229
Epidemiology of traumatic spine fractures
Leucht, Philipp; Fischer, Klaus; Muhr, Gert; Mueller, Ernst J
OBJECTIVES: To illustrate the correlations and effects of age, gender and cause of accident on the type of vertebral fracture and fracture distribution, as well as on the likelihood to sustain an associated injury or neurological deficit. DESIGN: Retrospective analysis of 562 patients with a traumatic fracture of the spine. Each patient was analysed by reviewing the medical records, the initial radiographs and CT-scans. SETTING: Level 1 trauma centre from 01/1996 to 12/2000. RESULTS: The most common cause of accident was a high-energy fall (39%), followed by traffic accidents (26.5%). While fall related fractures were evenly distributed over the whole spine, traffic accidents induced significantly more fractures of the cervical and thoracic spine. Sixty-five percent of all cervical spine fractures and 80% of the multisegmental injuries were accompanied by an associated injury. The highest incidence of associated injuries was observed in patients with multilevel fractures (96.5%). Patients with a concomitant injury were more likely to sustain a spinal cord lesion. Sixty-three (11.2%) patients exhibited a complete motor and sensory deficit, 76 (13.5%) an incomplete and 423 (75.3%) no neurological deficit. The highest number of complete motor and sensory neurological deficits was found in cervical spine fractures (19.7%). The majority of patients, 308 (54.8%), sustained a compression fracture, 95 (16.9%) a distraction fracture, and 104 (18.5%) patients experienced a rotational fracture. CONCLUSIONS: This study demonstrates correlations between the cause of accident, the type of spinal fracture and the fracture distribution. Using the AO classification, the likelihood to sustain either associated and/or spinal cord injuries, is predictable.
PMID: 19233356
ISSN: 0020-1383
CID: 1216422
Brief report: increased apoptosis in advanced atherosclerotic lesions of Apoe-/- mice lacking macrophage Bcl-2
Thorp, Edward; Li, Yankun; Bao, Liping; Yao, Pin Mei; Kuriakose, George; Rong, James; Fisher, Edward A; Tabas, Ira
OBJECTIVE: Macrophage apoptosis plays important roles in atherosclerosis. Bcl-2 is a key cell survival molecule, but its role in macrophage apoptosis in atherosclerosis is not known. The goal herein was to determine the effect of macrophage-targeted deletion of Bcl-2 on macrophage apoptosis in atherosclerotic lesions of Apoe(-/-) mice. METHODS AND RESULTS: Bcl2(flox)-LysMCre mice were created as a model of macrophage Bcl-2 deficiency. Macrophages from these mice were more susceptible to apoptosis than those from control Bcl2(WT)-LysMCre mice. The mice were bred onto the Apoe(-/-) background and fed a Western-type diet for 4 or 10 weeks. Apoptotic cells were equally very rare in the lesions of both groups of the 4-week-diet mice, and there was no difference in lesion area. However, Bcl2(flox)-LysMCre;Apoe(-/-) plaques from the 10-week-diet protocol had a 40% to 45% increase in apoptotic cells and, in female mice, a approximately 25% increase in plaque necrosis (P<0.05) compared with Bcl2(WT)-LysMCre lesions. CONCLUSIONS: Macrophage Bcl-2 plays a protective role against macrophage apoptosis specifically in advanced atherosclerotic lesions of Apoe(-/-) mice
PMCID:2731712
PMID: 18988889
ISSN: 1524-4636
CID: 133658
Mammalian fertilization: the strange case of sperm protein 56
Wassarman, Paul M
During mammalian fertilization sperm bind to the egg's zona pellucida (ZP) after undergoing capacitation. Capacitated mouse sperm bind to mZP3 (one of three ZP glycoproteins), undergo the acrosome reaction, penetrate the ZP, and fuse with egg plasma membrane. Sperm protein 56 (sp56), a member of the C3/C4 superfamily of binding proteins, was identified nearly 20 years ago as a binding partner for mZP3 by photoaffinity cross-linking of acrosome-intact sperm. However, subsequent research revealed that sp56 is a component of the sperm's acrosomal matrix and, for sperm with an intact acrosome, should be unavailable for binding to mZP3. Recently, this dilemma was resolved when it was recognized that some acrosomal matrix (AM) proteins, including sp56, are released to the sperm surface during capacitation. This may explain why uncapacitated mammalian sperm are unable to bind to the unfertilized egg ZP.
PMID: 19204987
ISSN: 0265-9247
CID: 1100032
Regulation of chondrocyte differentiation by ADAMTS-12 metalloproteinase depends on its enzymatic activity
Bai, X H; Wang, D W; Luan, Y; Yu, X P; Liu, C J
ADAMTS-12, a metalloproteinase that belongs to ADAMTS family, is strongly upregulated during chondrogenesis and demonstrates prominent expression in the growth plate chondrocytes. ADAMTS-12 potently inhibits chondrocyte differentiation, as revealed by altered expression of both early and later genes critical for chondrogenesis. In addition, ADAMTS-12-mediated inhibition of chondrogenesis depends on its enzymatic activity, since its point mutant lacking enzymatic activity completely loses this activity. Furthermore, the C-terminal four thrombospondin motifs known to bind COMP substrate is necessary for its full proteolytic activity and inhibition of chondrocyte differentiation. Mechanism studies demonstrate that ADAMTS-12 induces PTHrP, whereas it inhibits IHH during chondrogenesis. Furthermore, PTHrP induces ADAMTS-12 and ADAMTS-12 is hardly detectable in PTHrP-/-growth plate chondrocytes. Importantly, knocking down ADAMTS-12 mRNA levels or blocking ADAMTS-12 activity almost abolishes the PTHrP-mediated inhibition of type X collagen expression. Collectively, these findings demonstrate that ADAMTS-12, a downstream molecule of PTHrP signaling, is a novel regulator of chondrogenesis
PMID: 19151918
ISSN: 1420-9071
CID: 135229
Intracranial Microvascular Free Flaps
Levine, Steven; Garfein, Evan S; Weiner, Howard; Yaremchuk, Michael J; Saadeh, Pierre B; Gurtner, Geoffrey; Levine, Jamie P; Warren, Stephen M
Large acquired intracranial defects can result from trauma or surgery. When reoperation is required because of infection or tumor recurrence, management of the intracranial dead space can be challenging. By providing well-vascularized bulky tissue, intracranial microvascular free flaps offer potential solutions to these life-threatening complications. A multi-institutional retrospective chart and radiographic review was performed of all patients who underwent microvascular free-flap surgery for salvage treatment of postoperative intracranial infections between 1998 and 2006. A total of six patients were identified with large intracranial defects and postoperative intracranial infections. Four patients had parenchymal resections for tumor or seizure and two patients had posttraumatic encephalomalacia. All patients underwent operative debridement and intracranial free-flap reconstruction using the latissimus dorsi muscle ( N = 2), rectus abdominis muscle ( N = 2), or omentum ( N = 2). All patients had titanium ( N = 4) or Medpor ( N = 2) cranioplasties. We concluded that surgery or trauma can result in significant intracranial dead space. Treatment of postoperative intracranial infection can be challenging. Vascularized free tissue transfer not only fills the void, but also provides a delivery system for immune cells, antibodies, and systemically administered antibiotics. The early use of this technique when intracranial dead space and infection coexist is beneficial
PMID: 18925548
ISSN: 0743-684x
CID: 90063
SDF-1 alpha expression during wound healing in the aged is HIF dependent
Loh, Shang A; Chang, Edward I; Galvez, Michael G; Thangarajah, Hariharan; El-ftesi, Samyra; Vial, Ivan N; Lin, Darius A; Gurtner, Geoffrey C
BACKGROUND: Age-related impairments in wound healing are associated with decreased neovascularization, a process that is regulated by hypoxia-responsive cytokines, including stromal cell-derived factor (SDF)-1 alpha. Interleukin-1 beta is an important inflammatory cytokine involved in wound healing and is believed to regulate SDF-1 alpha expression independent of hypoxia signaling. Thus, the authors examined the relative importance of interleukin (IL)-1 beta and hypoxia-inducible factor (HIF)-1 alpha on SDF-1 alpha expression in aged wound healing. METHODS: Young and aged mice (n = 4 per group) were examined for wound healing using a murine excisional wound model. Wounds were harvested at days 0, 1, 3, 5, and 7 for histologic analysis, immunohistochemistry, enzyme-linked immunosorbent assay, and Western blot. An engineered wild-type and mutated SDF luciferase reporter construct were used to determine HIF transactivation. RESULTS: Aged mice demonstrated significantly impaired wound healing, reduced granulation tissue, and increased epithelial gap compared with young controls. Real-time polymerase chain reaction demonstrated reduced SDF-1 alpha levels in aged wounds that correlated with reduced CD31+ neovessels. Western blots revealed decreased HIF-1 alpha protein in aged wounds. However, both IL-1 beta and macrophage infiltrate were unchanged between young and aged animals. Using the wild-type and mutated SDF luciferase reporter construct in which the hypoxia response element was deleted, only young fibroblasts were able to respond to IL-1 beta stimulation, and this response was abrogated by mutating the HIF-binding sites. This suggests that HIF binding is essential for SDF-1 transactivation in response to both inflammatory and hypoxic stimuli. CONCLUSIONS: SDF-1 alpha deficiency observed during aged wound healing is attributable predominantly to decreased HIF-1 alpha levels rather than impaired IL-1 beta expression
PMID: 19182665
ISSN: 1529-4242
CID: 96554