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Featured researches published by James I. Cohen.


Otolaryngology-Head and Neck Surgery | 1994

Tumor angiogenesis, the p53 antigen, and cervical metastasis in squamous cell carcinoma of the tongue

Daniel A. Leedy; Dennis R. Trune; Joseph D. Kronz; Noel Weidner; James I. Cohen

A more accurate method of detecting nodal disease in squamous cell carcinoma of the tongue is needed so that treatment of the neck with its associated morbidity can safely be reserved for patients who actually have metastatic disease. Tumor angiogenesis and the expression of the p53 antigen—which have each been shown to be predictive of metastasis in breast and colon cancer, respectively—are examined for their ability to predict neck metastasis in tongue cancer. Fifty-seven patients with T1 and T2 squamous cell carcinoma of the oral tongue, whose neck disease was examined by dissection or by 2-year follow-up, were studied. Twenty-eight patients (49%) were node positive and 29 patients (51%) were node negative. The primary tumors were immunohistochemically stained for the p53 antigen and for factor VIII, which allowed the blood vessels within the tumor to be quantitated. The mean vessel counts per × 200 high-power field were 59.8 and 61.5 for node-positive and node-negative patients, respectively (p = 0.8). Node-positive patients showed overexpression of p53 43% of the time, vs. 61% for node-negative patients (p = 0.17). Multivariate analysis confirmed that no difference in tumor angiogenesis or the expression of the p53 antigen was found between tumors that had metastasized and those that had not. Therefore neither tumor angiogenesis nor the p53 tumor marker is clinically useful in determining lymph node metastasis in these patients.A more accurate method of detecting nodal disease in squamous cell carcinoma of the tongue is needed so that treatment of the neck with its associated morbidity can safely be reserved for patients who actually have metastatic disease. Tumor angiogenesis and the expression of the p53 antigen--which have each been shown to be predictive of metastasis in breast and colon cancer, respectively--are examined for their ability to predict neck metastasis in tongue cancer. Fifty-seven patients with T1 and T2 squamous cell carcinoma of the oral tongue, whose neck disease was examined by dissection or by 2-year follow-up, were studied. Twenty-eight patients (49%) were node positive and 29 patients (51%) were node negative. The primary tumors were immunohistochemically stained for the p53 antigen and for factor VIII, which allowed the blood vessels within the tumor to be quantitated. The mean vessel counts per x200 high-power field were 59.8 and 61.5 for node-positive and node-negative patients, respectively (p = 0.8). Node-positive patients showed overexpression of p53 43% of the time, vs. 61% for node-negative patients (p = 0.17). Multivariate analysis confirmed that no difference in tumor angiogenesis or the expression of the p53 antigen was found between tumors that had metastasized and those that had not. Therefore neither tumor angiogenesis nor the p53 tumor marker is clinically useful in determining lymph node metastasis in these patients.


Current Opinion in Otolaryngology & Head and Neck Surgery | 2004

Contemporary management of carotid blowout.

James I. Cohen; Ionel Rad

Purpose of reviewThe purpose of this report is to summarize existing literature with respect to carotid artery blowout and to present an up-to-date algorithm for its management that incorporates recent advances with respect to its diagnosis and treatment. Recent findingsAlthough once thought as one entity, carotid blowout is now considered to be a syndrome with clinical manifestations ranging from acute hemorrhage to asymptomatic exposure of a carotid artery. As a result, carotid blowout syndrome can present as one of three separate entities: threatened, impending, and acute carotid blowout. In recent years newer approaches to management have centered around the use of diagnostic angiography followed by definitive therapy with either carotid occlusion by coils, detachable balloons, or endovascular stents. Overall morbidity of management has decreased. SummaryInterventional radiologic techniques have revolutionized the treatment of carotid blowout syndrome, allowing more accurate diagnosis and lower treatment morbidity.


Annals of Otology, Rhinology, and Laryngology | 2002

Metallic tracheal stents: complications associated with long-term use in the upper airway.

Alan R. Burningham; Mark K. Wax; Peter E. Andersen; Edwin C. Everts; James I. Cohen

The use of metallic airway stents for the treatment of benign airway stenosis is increasingly advocated; however, the long-term safety and efficacy of these devices has not been established. Three case studies involving late but significant proximal tracheal stent complications are reported; 1 related to proximal mechanical stent failure and 2 related to obstructing granulation tissue and stenosis at the proximal stent orifice. Placement of these stents in close proximity to the cricotracheal junction is thought to be primarily responsible for these complications as a result of the excess shearing forces created at the stent-mucosal interface by the differential motion of the stent relative to the rigid subglottic airway and the more distensible trachea. Although the use of metallic stents remains appropriate in cases in which there is a defined and relatively short-term end point for treatment, caution is urged in using them in the proximal trachea for long-term management of benign airway disease.


Taxon | 2006

Are mitochondrial genes useful for the analysis of monocot relationships

Jerrold I. Davis; Gitte Petersen; Ole Seberg; Dennis W. Stevenson; Christopher R. Hardy; Mark P. Simmons; Fabián A. Michelangeli; Douglas H. Goldman; Lisa M. Campbell; Chelsea D. Specht; James I. Cohen

A phylogenetic analysis of monocots and related dicots was conducted, using a four-gene matrix consisting of two genes from the plastid genome (matK and rbcL) and two from the mitochondrial genome (atpA/atp1 and cob). The taxon sample includes 101 monocots and 36 dicots, and all four genes were sampled for all 137 taxa. Jackknife support was assessed for clades resolved by the four-gene analysis, and compared to support for the same clades by each of the four three-gene subset matrices, in order to quantify the degree to which each gene contributed to or detracted from support for each clade. Instances of positively and negatively correlated support for clades by genes of the same and different genomes were observed. In particular, the placement of Acorus within a clade that also includes Tofieldiaceae, Araceae, and Alismatales s.s., as opposed to its frequent placement as sister of all other monocots, is supported by atpA and matK. The results indicate that genes from the mitochondrial genome provide a unique test of relationships that have been inferred with plastid-encoded genes.


Current Opinion in Otolaryngology & Head and Neck Surgery | 2003

Current trends in management of Zenker diverticulum.

Elizabeth Veenker; James I. Cohen

Zenkers diverticulum is a relatively common problem encountered by head and neck surgeons. Careful review of the available literature regarding its pathogenesis indicates that Zenker diverticulum likely occurs as a result of increased intrabolus pressures during swallowing secondary to cricopharyngeal spasm. Rational treatment for Zenker diverticulum therefore addresses cricopharyngeal spasm. The traditional approach to diagnosis and management of Zenker diverticulum has been based on standard techniques and principles. For example, diverticulectomy with concurrent cricopharyngeal myotomy is an acceptable form of treatment with a high success rate. However, recent advances in endoscopic stapling and carbon dioxide laser technologies have added new options to the therapeutic armament of the otolaryngologist. For appropriately selected patients, endoscopic staple-assisted diverticulostomy is a minimally invasive, safe, and effective procedure associated with shorter hospital stays, more rapid postoperative recovery, decreased time to resumption of oral intake, and high levels of patient satisfaction.


American Journal of Botany | 2010

“A case to which no parallel exists”: The influence of Darwin’s Different Forms of Flowers

James I. Cohen

PREMISE OF THE STUDY Research on the subject of heterostyly is often traced back to 1877 when Charles Darwin published the landmark book The Different Forms of Flowers on Plants of the Same Species. This book synthesized heterostyly research at the time, much of which Darwin conducted, and it continues to be a major contribution to the study of the breeding system. In this book, Darwin discussed the ecology, morph-specific differences, self- and intramorph-incompatibility, evolution and origin, and floral development of heterostyly. Many of the hypotheses he proposed have been and continue to be tested. KEY RESULTS Throughout the 20(th) and 21(st) centuries, researchers have continued to identify new and different morph-specific floral characters, discover the mechanisms that underlie heteromorphic self-incompatibility, use phylogenies to examine the evolution of heterostyly, and determine novel floral developmental patterns in heterostylous species. From all of these studies, we have learned a great deal about the function, evolution, and development of heterostyly. CONCLUSIONS However, almost 150 years after Darwins publications on the subject of heterostyly, we still have a great deal to learn concerning the breeding system, and new technologies and techniques are allowing for new advances in heterostyly research to occur.


Annals of Otology, Rhinology, and Laryngology | 2002

Cricothyroid Approximation to Elevate Vocal Pitch in Male-to-Female Transsexuals: Results of Surgery

Caroline Y. Yang; Andrew D. Palmer; Toby R. Meltzer; Karen Drake Murray; James I. Cohen

Functional changes in voice production, including pitch elevation, may help male-to-female transsexuals assume a new gender identity. To date, there has been a paucity of objective data on the effectiveness of pitch-raising methods. Acoustic data were gathered with regard to preoperative and postoperative changes in pitch, pitch range, and perturbation in 20 patients after cricothyroid approximation. Subjective data were gathered by means of a mailed questionnaire. The mean follow-up time was 22 months. The speaking fundamental frequency was raised by half an octave without any significant changes in perturbation. The lower and upper limits of pitch range both increased by an average of 4 semitones. There was some decline over time of the lower pitch range toward preoperative levels, but the upper pitch range remained elevated. The majority of the patients were satisfied with the results of surgery and felt their voices to be more feminine.


Plastic and Reconstructive Surgery | 1996

The rat ventral island flap: a comparison of the effects of reduction in arterial inflow and venous outflow.

Adrian P. Roberts; James I. Cohen; Ted A. Cook

The relative importance of reduced arterial inflow versus reduced venous outflow in determining flap necrosis remains undefined, even though this is critically important in understanding the effects of pharmacologic agents on flap survival. By means of a rat bipedicled ventral island flap, the amount of random flap necrosis was examined in four experimental groups: (1) unilateral arteriovenous ligation (n = 19), (2) unilateral vein ligation (n = 20), (3) unilateral artery ligation (n = 20), and (4) alternate side vein and artery ligation (n = 18). No necrosis occurred on the side of the vein ligation in groups 2 and 4, indicating that independently reducing venous outflow does not cause flap necrosis. A predictable necrosis occurred ipsilateral to artery ligation in groups 1 (37.63 +/- 17.34 percent), 3 (32.74 +/- 17.32 percent), and 4 (15.70 +/- 9.86 percent). These data indicate that the rat ventral island flap is more sensitive to a decrease in arterial inflow than to a decrease in venous outflow. This model may therefore be useful in clarifying the effect and determining the mechanism of action of pharmacologic agents that alter flap survival.


Cladistics | 2014

A phylogenetic analysis of morphological and molecular characters of Boraginaceae: evolutionary relationships, taxonomy, and patterns of character evolution

James I. Cohen

The angiosperm family Boraginaceae includes ca. 1600 species distributed among ca. 110 genera. Some floral features are constant within the family, but many vegetative, floral, pollen, and nutlet traits vary. Utilizing 224 species of Boraginaceae and related taxa, five matrices were constructed with various combinations of morphological characters, three chloroplast DNA regions, and one nuclear ribosomal DNA region. Phylogenetic analyses were conducted for these matrices, and patterns of character evolution were examined. Boraginaceae is resolved as monophyletic, with Wellstedia as its sister. Codon is sister to Boraginaceae + Wellstedia. Although most of the investigated morphological characters have a low consistency index, particular character states are synapomorphies for large clades in each of the tribes of the family. In Boraginaceae, the breeding system heterostyly evolved at least 12 times, which is the largest number of origins resolved in any family; therefore Boraginaceae can serve as a model for the evolution and development of heterostyly. Nutlet ornamentation is most diverse in Cynoglosseae and Trichodesmeae, while pollen and floral features are most variable in Boragineae and Lithospermeae. Phylogenetic relationships and patterns of character evolution identified in the present study set the stage for future work creating an updated taxonomic system of Boraginaceae.


Cladistics | 2011

A phylogenetic analysis of morphological and molecular characters of Lithospermum L. (Boraginaceae) and related taxa: evolutionary relationships and character evolution

James I. Cohen

Lithospermum (Boraginaceae) includes ca. 60 species and exhibits a wide range of floral, palynological, and vegetative diversity. Phylogenetic analyses based on 10 chloroplast DNA regions and 22 morphological characters were conducted in order to (i) examine evolutionary relationships within Lithospermum and among related genera of Boraginaceae, and (ii) investigate patterns of morphological evolution. Several morphological features, such as long‐funnelform corollas, faucal appendages, reciprocal herkogamy, and evident secondary leaf venation, have evolved multiple times within the genus. In contrast, other morphological features, including the presence of glands and the position and number of pollen pores, are less plastic and tend to characterize larger clades. Some features, including the presence of glands, are interpreted as symplesiomorphic for Lithospermum, while others, such as evident secondary leaf venation, appear to have originated repeatedly. The range of structural diversity that occurs among the species of Lithospermum suggests the potential utility of this genus as a model for integrative studies of evolution, development, and molecular biology.© The Willi Hennig Society 2011.

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Ming-Li Zhang

Chinese Academy of Sciences

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