Publications
Department of Medicine faculty members published more than 3,600 peer-reviewed articles in 2024.
2006
BACKGROUND
With the recent development of endoscopic submucosal dissection (ESD), large oesophageal cancers can be removed with a single procedure, with few limits on the resectable range. However, after aggressive ESD, a major complication that arises is postoperative inflammation and stenosis that can considerably affect the patient's quality of life.
AIMS
To examine a novel treatment combining ESD and the endoscopic transplantation of tissue-engineered cell sheets created using autologous oral mucosal epithelial cells, in a clinically relevant large animal model.
METHODS
Oral mucosal epithelial cells, harvested from beagle dogs, were cultured under normal conditions at 37 degrees C, on temperature-responsive dishes. After ESD (5 cm in length, 180 degrees in range), cell sheets were harvested by a simple reduction in temperature to 20 degrees C, and transplanted by endoscopy.
RESULTS
The transplanted cell sheets were able to adhere to and survive on the underlying muscle layers in the ulcer sites, providing an intact, stratified epithelium. Four weeks after surgery, complete wound healing, with no observable stenosis, was seen in the animals receiving autologous cell sheet transplantation. By contrast, noticeable fibrin mesh and host inflammation, consistent with the intermediate stages of wound healing, were observed in the control animals that received only ESD.
CONCLUSIONS
These findings in a clinically relevant canine model show the effectiveness of a novel combined endoscopic approach for the potential treatment of oesophageal cancers that can effectively enhance wound healing and possibly prevent postoperative oesophageal stenosis.
View on PubMed2006
2006
Activation of latent TGF-beta by the alpha(v)beta6 integrin is a critical step in the development of acute lung injury. However, the mechanism by which alpha(v)beta6-mediated TGF-beta activation is regulated has not been identified. We show that thrombin, and other agonists of protease-activated receptor 1 (PAR1), activate TGF-beta in an alpha(v)beta6 integrin-specific manner. This effect is PAR1 specific and is mediated by RhoA and Rho kinase. Intratracheal instillation of the PAR1-specific peptide TFLLRN increases lung edema during high-tidal-volume ventilation, and this effect is completely inhibited by a blocking antibody against the alpha(v)beta6 integrin. Instillation of TFLLRN during high-tidal-volume ventilation is associated with increased pulmonary TGF-beta activation; however, this is not observed in Itgb6-/- mice. Furthermore, Itgb6-/- mice are also protected from ventilator-induced lung edema. We also demonstrate that pulmonary edema and TGF-beta activity are similarly reduced in Par1-/- mice following bleomycin-induced lung injury. These results suggest that PAR1-mediated enhancement of alpha(v)beta6-dependent TGF-beta activation could be one mechanism by which activation of the coagulation cascade contributes to the development of acute lung injury, and they identify PAR1 and the alpha(v)beta6 integrin as potential therapeutic targets in this condition.
View on PubMed2006
2006
The saturated C20 isoprenoid phytanic acid is physiologically derived from phytol released in the degradation of chlorophyll. The presence of a C-3 methyl group in this substrate blocks normal beta-oxidation, so phytanic acid degradation primarily occurs by initial peroxisomal alpha-oxidation to shift the register of the methyl group. However, individuals with Refsum's disease are genetically deficient in the required phytanoyl-CoA alpha-hydroxylase and suffer from neurological pathologies caused by the accumulation of phytanic acid. Recent work has shown that phytanic acid can also be catabolized by a pathway initiated by omega-hydroxylation of the hydrocarbon chain, followed by oxidation of the alcohol to the acid and conventional beta-oxidation. However, the enzymes responsible for the omega-hydroxylation of phytanic acid have not been identified. In this study, we have determined the activities of all of the rat and human CYP4A enzymes and two of the rat CYP4F enzymes, with respect to the omega-hydroxylation of phytanic acid. Furthermore, we have shown that the ability to omega-hydroxylate phytanic acid is elevated in microsomes from rats pretreated with clofibrate. The results support a possible role for CYP4 enzyme elevation in the elimination of phytanic acid in Refsum's disease patients.
View on PubMed2006
2006
BACKGROUND
Urinary incontinence is common in women. Because treatments differ, urge incontinence should be distinguished from stress incontinence. To make this distinction, current guidelines recommend an extensive evaluation that is too time-consuming for primary care practice.
OBJECTIVE
To test the accuracy of a simple questionnaire to categorize type of urinary incontinence in women.
DESIGN
Multicenter, prospective study of the accuracy of the 3 Incontinence Questions (3IQ) compared with an extended evaluation to distinguish between urge incontinence and stress incontinence.
SETTING
5 academic medical centers in the United States.
PARTICIPANTS
301 women enrolled from April to December 2004 who were older than 40 years of age (mean age, 56 years [SD, 11]) with untreated incontinence for an average of 7 years (SD, 7) and a broad range of incontinence severity.
MEASUREMENTS
All participants included in the analyses answered the 3IQ questionnaire, and a urologist or urogynecologist who was blinded to the responses performed the extended evaluation. Sensitivity, specificity, and likelihood ratios were determined for the 3IQ.
RESULTS
For classification of urge incontinence and with the extended evaluation as the gold standard, the 3IQ had a sensitivity of 0.75 (95% CI, 0.68 to 0.81), a specificity of 0.77 (CI, 0.69 to 0.84), and a positive likelihood ratio of 3.29 (CI, 2.39 to 4.51). For classification of stress incontinence, the sensitivity was 0.86 (CI, 0.79 to 0.90), the specificity was 0.60 (CI, 0.51 to 0.68), and the positive likelihood ratio was 2.13 (CI, 1.71 to 2.66).
LIMITATIONS
Participants were enrolled by urologists and urogynecologists at academic medical centers.
CONCLUSIONS
The 3IQ questionnaire is a simple, quick, and noninvasive test with acceptable accuracy for classifying urge and stress incontinence and may be appropriate for use in primary care settings. Similar studies are needed in other populations. We also need a clinical trial comparing the outcomes of treatments based on the 3IQ and the extended evaluation.
View on PubMed2006
2006
2006