Gene and protein expression of Transforming growth factor Β 2 gene during murine primary palatogenesis

The molecular mechanisms by which the primordia of the midface grow and fuse to form the primary palate are not well characterized. This is in spite of the fact that failure of growth and/or fusion of these facial primordia leads to the common human craniofacial birth defects, clefts of the lip with or without clefts of the palate. Members of the transforming growth factor Β ( Tgf Β) superfamily have been shown to play critical roles during craniofacial development. Specifically, the role of Tgf Β -3 in mediating the fusion of the embryonic secondary palatal shelves is well documented. In a screen for genes expressed during fusion of the murine midfacial processes, Tgf Β 2 was identified as a gene differentially expressed during fusion of the lateral and medial nasal processes. The objective of our study was to analyze the spatial and temporal expression of Tgf Β 2 during critical stages of midfacial morphogenesis at both the transcript and protein levels. We also compared the pattern of expression of Tgf Β 2 with that of Bmp4 , a gene shown previously to be involved in mediating the fusion process in the midface. Our results showed Tgf Β 2 expression in a very restrictive area of the epithelial layer along the borders of the midfacial primordia, in a pattern very similar to that of Bmp4 . The highly restrictive and spatial and temporal pattern of expression of Tgf Β 2 implicates its role in mediating the fusion of the midfacial processes, possibly through interacting with Bmp4 in the regulation of apoptosis and/or epithelial–mesenchymal transformation. A greater understanding of the role of this gene will clarify how the normal midface grows and the mechanisms behind cleft development.Peer Reviewedhttp://deepblue.lib.umich.edu/bitstream/2027.42/72512/1/j.1432-0436.2005.00022.x.pd

Regulation of limb patterning by extracellular microfibrils

To elucidate the contribution of the extracellular microfibril–elastic fiber network to vertebrate organogenesis, we generated fibrillin 2 (Fbn2)–null mice by gene targeting and identified a limb-patterning defect in the form of bilateral syndactyly. Digit fusion involves both soft and hard tissues, and is associated with reduced apoptosis at affected sites. Two lines of evidence suggest that syndactily is primarily due to defective mesenchyme differentiation, rather than reduced apoptosis of interdigital tissue. First, fusion occurs before appearance of interdigital cell death; second, interdigital tissues having incomplete separation fail to respond to apoptotic clues from implanted BMP-4 beads. Syndactyly is associated with a disorganized matrix, but with normal BMP gene expression. On the other hand, mice double heterozygous for null Fbn2 and Bmp7 alleles display the combined digit phenotype of both nullizygotes. Together, these results imply functional interaction between Fbn2-rich microfibrils and BMP-7 signaling. As such, they uncover an unexpected relationship between the insoluble matrix and soluble factors during limb patterning. We also demonstrate that the Fbn2- null mutation is allelic to the recessive shaker-with-syndactyly (sy) locus on chromosome 18

The Receptor Activator of Nuclear Factor-κB Ligand-mediated Osteoclastogenic Pathway Is Elevated in Amelogenin-null Mice

Amelogenins, major components of developing enamel, are predominantly involved in the formation of tooth enamel. Although amelogenins are also implicated in cementogenesis, their precise spatial expression pattern and molecular role are not clearly understood. Here, we report for the first time the expression of two alternate splice forms of amelogenins, M180 and the leucine-rich amelogenin peptide (LRAP), in the periodontal region of mouse tooth roots. Lack of M180 and LRAP mRNA expression correlated with cementum defects observed in the amelogenin-null mice. The cementum defects were characterized by an increased presence of multinucleated cells, osteoclasts, and cementicles. These defects were associated with an increased expression of the receptor activator of the nuclear factor-kappa B ligand (RANKL), a critical regulator of osteoclastogenesis. These findings indicate that the amelogenin splice variants, M180 and LRAP, are critical in preventing abnormal resorption of cementum

Tenecteplase for ST-elevation myocardial infarction in a patient treated with drotrecogin alfa (activated) for severe sepsis: a case report

<p>Abstract</p> <p>Introduction</p> <p>Drotrecogin alfa (activated) (DrotAA), an activated protein C, promotes fibrinolysis in patients with severe sepsis. There are no reported cases or studies that address the diagnosis and treatment of myocardial infarction in septic patients treated with DrotAA.</p> <p>Case presentation</p> <p>A 59-year-old Caucasian man with septic shock secondary to community-acquired pneumonia treated with DrotAA, subsequently developed an ST-elevation myocardial infarction 12 hours after starting DrotAA. DrotAA was stopped and the patient was given tenecteplase thrombolysis resulting in complete resolution of ST-elevation and no adverse bleeding events. DrotAA was restarted to complete the 96-hour course. The sepsis resolved and the patient was discharged from hospital.</p> <p>Conclusion</p> <p>In patients with severe sepsis or septic shock complicated by myocardial infarction, it is difficult to determine if the myocardial infarction is an isolated event or caused by the sepsis process. The efficacy and safety of tenecteplase thrombolysis in septic patients treated with DrotAA need further study.</p

Large-Scale Phenotyping of an Accurate Genetic Mouse Model of JNCL Identifies Novel Early Pathology Outside the Central Nervous System

Cln3Δex7/8 mice harbor the most common genetic defect causing juvenile neuronal ceroid lipofuscinosis (JNCL), an autosomal recessive disease involving seizures, visual, motor and cognitive decline, and premature death. Here, to more thoroughly investigate the manifestations of the common JNCL mutation, we performed a broad phenotyping study of Cln3Δex7/8 mice. Homozygous Cln3Δex7/8 mice, congenic on a C57BL/6N background, displayed subtle deficits in sensory and motor tasks at 10–14 weeks of age. Homozygous Cln3Δex7/8 mice also displayed electroretinographic changes reflecting cone function deficits past 5 months of age and a progressive decline of retinal post-receptoral function. Metabolic analysis revealed increases in rectal body temperature and minimum oxygen consumption in 12–13 week old homozygous Cln3Δex7/8mice, which were also seen to a lesser extent in heterozygous Cln3Δex7/8 mice. Heart weight was slightly increased at 20 weeks of age, but no significant differences were observed in cardiac function in young adults. In a comprehensive blood analysis at 15–16 weeks of age, serum ferritin concentrations, mean corpuscular volume of red blood cells (MCV), and reticulocyte counts were reproducibly increased in homozygous Cln3Δex7/8 mice, and male homozygotes had a relative T-cell deficiency, suggesting alterations in hematopoiesis. Finally, consistent with findings in JNCL patients, vacuolated peripheral blood lymphocytes were observed in homozygous Cln3Δex7/8 neonates, and to a greater extent in older animals. Early onset, severe vacuolation in clear cells of the epididymis of male homozygous Cln3Δex7/8 mice was also observed. These data highlight additional organ systems in which to study CLN3 function, and early phenotypes have been established in homozygous Cln3Δex7/8 mice that merit further study for JNCL biomarker development