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Biomedical subjects

Michael J Terry

Publications and source records attributed to Michael J Terry.

7 recordsLinked to original sources

A case of unilateral coronal synostosis in a child with craniofacial microsomia.

Craniofacial microsomia is a congenital malformation complex associated with a wide array of craniofacial and extracraniofacial anomalies. Frontal plagiocephaly has been shown to occur in approximately 5% to 12% of patients with craniofacial microsomia. The etiology of craniofacial microsomia-associated frontal plagiocephaly is unclear; of the cases described in the literature, all but one had physical findings suggestive of deformational plagiocephaly. In the case with equivocal physical findings, radiographic studies showed no evidence of craniosynostosis. Unlike the above cases, we report a documented case of radiologically-confirmed unilateral coronal synostosis in a child with craniofacial microsomia.

Craniofacial Abnormalities↗

Primary sequence independence for prion formation.

Many proteins can adopt self-propagating beta-sheet-rich structures, termed amyloid fibrils. The [URE3] and [PSI+] prions of Saccharomyces cerevisiae are infectious amyloid forms of the proteins Ure2p and Sup35p, respectively. Ure2p forms prions primarily as a result of its sequence composition, as versions of Ure2p with the prion domain amino acids shuffled are still able to form prions. Here we show that prion induction by both Ure2p and Ure2-21p, one of the scrambled versions of Ure2p, is clearly dependent on the length of the inducing fragment. For Ure2-21p, no single sequence is found in all of the inducing fragments, highlighting the sequence independence of prion formation. Furthermore, the sequence of the Sup35p prion domain can also be randomized without blocking prion formation. Indeed, a single shuffled sequence could give rise to several prion variants. These results suggest that [PSI+] formation is driven primarily by the amino acid composition of the Sup35p prion domain, and that the Sup35p oligopeptide repeats are not required for prion maintenance.

Amino Acid Sequence↗

Lentiviral gene therapy with platelet-derived growth factor B sustains accelerated healing of diabetic wounds over time.

The treatment of diabetic wounds is a formidable clinical challenge. In this study, lentiviral vectors carrying the human platelet-derived growth factor B (PDGF-B) gene were used to treated diabetic mouse wounds. Full-thickness 2.0-cm x 2.0-cm excisional wounds were created on the dorsa of genetically diabetic C57BL/KsJ-m+/+Lepr(db) mice. Lentiviral vectors containing the PDGF-B gene were injected into the wound margins and base. Mice were killed at 14-, 21-, and 35-day intervals. Measurement of the residual epithelial gap showed a trend towards increased healing in lentiviral PDGF-treated wounds compared with untreated and saline-treated wounds at all time points. At 21 days, there was significantly increased healing in lentiviral PDGF-treated wounds (0.98+/-0.17 cm) compared with saline-treated wounds (1.22+/-0.30 cm; P<0.05). Immunohistochemistry for CD31 revealed significantly increased neovascularization in lentiviral PDGF-treated wounds compared with untreated and saline-treated wounds at 14 and 21 days (P<0.01). Picrosirius red staining demonstrated thicker and more highly organized collagen fibers in treated wounds compared with untreated and saline-treated wounds. Quantitative analysis of collagen content showed a 3.5-fold and 2.3-fold increase in lentiviral PDGF-treated wounds versus untreated and saline-treated wounds, respectively (P<0.01). Lentiviral gene therapy with PDGF-B can sustain diabetic wound healing over time and may possess promising potential in the clinical setting.

Analysis of Variance↗

A comprehensive catalog of CpG islands methylated in human lung adenocarcinomas for the identification of tumor suppressor genes.

CpG island methylation is an important mechanism in gene silencing and is a key epigenetic event in cancer development. As yet, the number and identities of the genes that are inactivated in cancer cells has not been determined. In order to address this issue, we have performed a comprehensive isolation of CpG islands that are methylated in human lung adenocarcinomas. We have isolated approximately 200 CpG islands that are methylated in tumor DNA including those of known tumor-associated genes such as the HOXA5 gene. As the library contains the CpG islands of a number of known tumor suppressor genes it is highly likely that additional, previously unidentified tumor suppressor genes, will be present. On average, 1-2% of CpG islands were methylated specifically in tumors although this figure differed greatly between patients. This study provides an important resource in the search for genes inactivated in tumors and for the investigation of epigenetic dysregulation of gene expression by CpG island methylation.

Adenocarcinoma↗

HOX gene clusters are hotspots of de novo methylation in CpG islands of human lung adenocarcinomas.

CpG island methylation results in the silencing of the associated gene and is an important step in tumorigenesis. Following a comprehensive isolation of CpG islands that were methylated in human lung adenocarcinoma, we found that in cancer cells de novo CpG island methylation generally occurred in a sporadic manner. However, some methylated CpG islands appeared to cluster in discrete chromosomal regions. In this study, we have investigated the methylation status of CpG islands located at such chromosomal loci. We have found that many CpG islands at the HOXA and HOXD loci were methylated in human lung adenocarcinoma. The de novo methylation of these CpG islands was also observed in patient's DNA from noncancerous portions of lung tissue. These results indicate the presence of specific chromosomal regions that are susceptible to de novo methylation.

Adenocarcinoma↗