Cervical Spine Movement in a Cadaveric Model of Severe Spinal Instability: A Study Comparing Tracheal Intubation with 4 Different Laryngoscopes.

BACKGROUND: This study compared the Macintosh blade direct laryngoscope, Glidescope, C-Mac d-Blade, and McGrath MAC X-blade video laryngoscopes in 2 cadaveric models with severe cervical spinal instability. We hypothesized that the Glidescope video laryngoscope would allow for intubation with the least amount of cervical spine movement. Our secondary endpoints were glottic visualization and intubation success. METHODS: In total, 2 fresh cadavers underwent maximal surgical destabilization from the craniocervical junction to the cervicothoracic junction by a neurosurgical spine specialist, with subsequent neutral positioning of the heads with surgical head fixation devices. On each cadaver, 8 experienced anesthesiologists performed four intubations with the 4 laryngoscopes in random order. Lateral radiographic measurements determined vertebral displacement during intubation. RESULTS: Cervical spine displacements were not significantly different amongst video laryngoscopes. Cormack-Lehane Grade 1 views were achieved with all attempts with each of the 3 video laryngoscopes; intubation attempts with the Macintosh blade achieved only grade 3 or grade 4 views. Intubation was successful every time with a video laryngoscope but only during 1 of 16 intubation attempts with the Macintosh blade. CONCLUSIONS: In a cadaveric model with maximally destabilized cervical spines, cervical spine movement was observed during attempted laryngoscopy using each of 3 video laryngoscopes, although there was no significant difference between the laryngoscopes. Given cervical spine displacement occurred, these video laryngoscopes do not prevent cervical spine motion during laryngoscopy. However, with improved glottic visualization and intubation success, video laryngoscopes are superior to the Macintosh blade in both cervical spine safety and intubation efficacy in the model studied.

Multivariate analysis of factors associated with smoking cessation in women.

BACKGROUND: Appropriate smoking cessation techniques, including counseling patients to stop smoking, could prevent multiple health-related problems. Identification of relevant factors in patients that smoke may be beneficial in targeting smoking cessation efforts. This investigation explores various factors associated with smoking cessation, specifically in women. METHODS: All women (n = 675) presenting to a breast health center over a one year period were surveyed regarding their tobacco use. Any association between smoking cessation and various factors was determined by multivariate analysis. RESULTS: Our population consisted of 47% African American women, 43% Caucasian women, and 10% women of other ethnicities. Sixty percent of all women never smoked. Of the women who had smoked, 57% quit. Except for alcohol use and exercise, no factor, including ethnicity, was associated with never smoking. Smoking cessation was associated with being married, being Caucasian, not using alcohol, and exercising. However, only Caucasian race and marriage were independently associated with smoking cessation. DISCUSSION: In our population, African American women had a lower proportion of smoking cessation than Caucasian women. In patients with similar access to care, specifically preventive care, there are ethnic and social differences in smoking cessation.

Discrimination of benign and malignant thyroid nodules by molecular profiling.

BACKGROUND: The evaluation of thyroid nodules by fine-needle aspiration has been the standard for almost 30 years, despite significant shortcomings in sensitivity and specificity. Recent data from our laboratory have suggested that molecular profiling permits the discrimination of specific types of thyroid nodules. These studies were undertaken to determine whether molecular profiling can discriminate between benign and malignant thyroid nodules with the necessary sensitivity and specificity required of a screening test. METHODS: Molecular profiles of 11 papillary thyroid carcinomas, 13 follicular variant of papillary thyroid carcinomas, 9 follicular thyroid carcinomas, and 26 benign tumors (follicular adenomas and hyperplastic nodules) were analyzed by oligonucleotide microarray analysis. A gene list was created based on 45 samples. Seventeen samples were then added to the analysis as unknowns. A hierarchical clustering analysis was performed on all 62 samples to examine the groups for potential differences and the ability of the gene list to distinguish tumor types. RESULTS: Cluster analysis of all 62 samples produced 2 distinct groups, 1 containing the carcinomas and 1 containing the benign lesions. The sensitivity for a diagnosis of cancer was 91.7% with a specificity of 96.2% (3 follicular variant of papillary thyroid carcinomas clustered with the benign lesions). The cancer gene profiles contained both known cancer-associated genes (MET, galectin-3) and previously unidentified genes. CONCLUSIONS: Molecular profiling readily distinguishes between benign and malignant thyroid tumors with excellent sensitivity and specificity. Elucidated genes may provide insight into the molecular pathogenesis of thyroid cancer. Gene profiling may significantly enhance the evaluation of thyroid nodules in the future.

Classification of follicular thyroid tumors by molecular signature: results of gene profiling.

PURPOSE: Thyroid nodules are common, with a lifetime risk of developing a clinically significant thyroid nodule of 10% or higher. Preoperative diagnosis was greatly enhanced by the introduction of fine needle aspiration in the 1970s, but there has been little advancement since that time. Discrimination between benign and malignant follicular neoplasms is currently not possible by fine needle aspiration and can even be difficult after full pathologic review. The purpose of these studies is to identify genes expressed in follicular adenomas and carcinomas of the thyroid that will permit molecular differentiation of these neoplasms. EXPERIMENTAL DESIGN: Gene expression patterns of 17 thyroid follicular tumors were analyzed by oligonucleotide array analysis. Gene profiles for follicular adenomas and carcinomas were identified, and the two groups were compared for differences in expression levels. The differentially expressed genes were used to perform a hierarchical clustering analysis training set. Five follicular tumors with diagnosis undisclosed to the investigators and 2 minimally invasive carcinomas were entered into the cluster analysis as a test set to determine whether diagnosis by gene profile correlated with that obtained by pathologic evaluation. RESULTS: Thyroid follicular adenomas and carcinomas showed strikingly distinct gene expression patterns. The expression patterns of 105 genes were found to be significantly different between follicular adenoma and carcinoma. Many uncharacterized genes contributed to the distinction between tumor types. For five follicular tumors for which the final diagnosis was undisclosed, the clustering algorithm gave the correct diagnosis in all 5 cases. CONCLUSIONS: Gene profiling is a useful tool to predict the molecular diagnosis of follicular thyroid tumors. Genes were identified that reliably differentiate follicular thyroid carcinoma from adenoma. This study provides insight into genes that may be important in the molecular pathogenesis of follicular thyroid tumors, as well candidates for preoperative diagnosis of follicular thyroid carcinoma.

Renal cell carcinoma induces prostaglandin E2 and T-helper type 2 cytokine production in peripheral blood mononuclear cells.

BACKGROUND: Patients with renal cell carcinoma (RCC) do not develop an effective antitumor immune response, despite significant infiltration by lymphocytes. Tumor production of immunosuppressive factors may account for this failure. The object of this study was to investigate the production of immunosuppressive mediators, especially prostaglandin E(2) (PGE(2)), by RCC. METHODS: Peripheral blood mononuclear cells (PBMC) were cocultured with conditioned medium (CM) from human RCC cell lines in the presence or absence of NS-398, a selective cyclooxygenase 2 (COX-2) inhibitor. Supernatants were analyzed for levels of PGE(2), interleukin (IL)-10, IL-6, IL-2, interferon-gamma, and IL-12. The effects of RCC CM on PBMC proliferation were also examined. The expression of basal and stimulated COX-2 messenger RNA in the cell lines was assessed by reverse transcriptase-polymerase chain reaction. RESULTS: RCC CM significantly increased PGE(2) production by PBMC. T-helper type 2 (Th2) cytokine production was also significantly increased. Th1 cytokines were unchanged or decreased. RCC CM increased proliferation of PBMC. Coculture with NS-398 reduced PBMC PGE(2) production to below control levels and significantly decreased IL-6 production and PBMC proliferation. NS-398 had no effect on cellular production of IL-10 or Th1 cytokines. CONCLUSIONS: Human RCC inhibits the host antitumor immune response by promoting PGE(2) production and Th2 cytokines in PBMC. Selective inhibition of COX-2 may have a role in abrogating this effect.

Serum leptin levels in acute protein deprivation.

BACKGROUND: Protein energy malnutrition (PEM) induces a host neuroendocrine response, reflected by significant elevations in circulating glucocorticoid levels and associated with metabolic and immune dysfunction. Leptin regulates food intake and body mass and has a significant impact on the hypothalamic-pituitary-adrenal axis (HPA). We hypothesized that leptin may be altered by and may play an important role in regulating the effects of PEM. METHODS: Female Balb/c mice were used. In experiment 1, mice were pair-fed either a protein-free (0% casein) or control (24% casein) diet for 7 days. In experiment 2, mice were implanted with either a placebo or corticosterone-releasing pellet and fed the control diet for 7 days. In experiment 3, adrenalectomized mice were pair-fed either the protein-free or control diet for 7 days. Serum corticosterone and leptin levels were measured in all experiments. RESULTS: PEM caused significant reductions in food intake, body weight, and total body fat, but not lean body mass. Serum corticosterone and leptin levels were significantly greater in mice fed the protein-free diet. Subcutaneous implantation of a corticosterone pellet in mice fed the control diet resulted in a significantly elevated serum leptin level compared with placebo-implanted controls. Bilateral adrenalectomy partially blunted the increased serum leptin in PEM. CONCLUSIONS: Leptin may be an important mediator of weight loss and decreased food intake in PEM. Elevated serum leptin in PEM may be secondary to elevated serum corticosterone, with other factors inherent in the host response to protein restriction also contributing to elevated serum leptin.

Antisense hTERT inhibits thyroid cancer cell growth.

Activation of telomerase represents an early step in carcinogenesis. Increased telomerase expression in malignant thyroid tumors suggests that inactivation of telomerase may represent a potential chemotherapeutic target. The purpose of this study was to inhibit the protein component of telomerase, hTERT, in a human thyroid cancer cell line in vitro and in vivo using an antisense strategy. A 235-bp fragment of hTERT cDNA was subcloned, and sense and antisense hTERT expression vectors were constructed. These vectors were transfected into a human thyroid carcinoma cell line (FRO). Tumorigenic potential was determined by cellular growth assay, rate of apoptosis, anchorage-independent growth, and tumor growth in a nude mouse model. Significant down-regulation of hTERT expression was seen in the antisense transfected cells, compared with control and those transfected with the sense vector. A decrease in telomerase activity by TRAP assay was observed in the antisense hTERT cells but not in cells transfected with the sense hTERT construct. Inhibition of cell growth was observed after approximately 20 population doublings in the antisense-hTERT clones and was associated with an increase in the rate of apoptosis and a change in cellular morphology. Moreover, anchorage-independent growth was reduced in vitro, and tumor growth rate was diminished in vivo in the antisense hTERT clones. Inhibition of telomerase activity with antisense hTERT in human thyroid cancer cells is achievable and may represent a novel target to inhibit tumor growth.

Self-reported differences in daily raw vegetable intake by ethnicity in a breast screening program.

PURPOSE: While the literature has no conclusive causal relationship between nutrition and breast cancer, diet is believed to play a role in the development of breast cancer. This investigation focuses on differences of dietary practice between Caucasians and African Americans in a cohort of women presenting for breast cancer screening. METHODS: Over a one-year period, 675 women presenting to the Breast Health Center at Tulane University Medical Center for an initial visit were given a self-reported health behavior questionnaire. Included in this survey were questions concerning the frequency of raw vegetable consumption and fat/oil intake. MAIN FINDINGS: The overall proportion of women who presented for breast cancer screening that reported daily raw vegetable consumption in the study group was 40%. There were statistically significant differences between proportions of Caucasian women's and African American women's consumption of daily raw vegetable (51% versus 29%, respectively; P < 0.0001). These differences were not seen in daily fat/oil intake. No differences were seen in socioeconomic measures. CONCLUSIONS: There is a substantial difference in the consumption of potentially protective foods among major ethnic groups. These dietary differences should be taken into account when investigating the ethnic differences in women with breast cancer, as well as the relationship between breast cancer and nutrition.

Effects of limited work hours on surgical training.

BACKGROUND: Legal mandates to reduce resident work hours have prompted changes in the structure of surgical training programs. Such changes have included modification of on-call schedules and the adoption of "night float" resident coverage. Little is known about the effects of these changes on surgical resident education and perceptions of quality of patient care. STUDY DESIGN: The surgical housestaff and faculty at a single institution completed a 21-point Likert survey. Subjects were asked to compare parameters of resident education, patient care, and resident quality of life before and after institution of a strict 80-hour work week resident training schedule. The number of hours worked per week before and after these changes were reported. American Board of Surgery In-Training Examination (ABSITE) scores were compared for the 2 years before and after implementation of this schedule. Total number of surgical cases performed by graduating chief residents were recorded and compared for the 3 years before and after the schedule changes. RESULTS: Resident work hours reduced significantly after schedule changes were implemented. A majority of surgical residents reported an improvement in quality of life, but residents and faculty perceived changes to have a negative impact on continuity of patient care. Mean ABSITE composite percentile scores significantly improved after the reduction of working hours. ABSITE scores for junior residents improved significantly; no significant differences were noted in scores for senior residents. CONCLUSIONS: Reduction in resident work hours has salutary effects on perception of quality of life and basic education for surgical residents. These benefits may come at the expense of patient care, particularly continuity of care. This study did not directly assess patient outcomes but the perceptions of caregivers suggest that patient care may be compromised. Further research is needed to assess the longterm effects of changes on both residents and patients.

Socioeconomic Factors, not Ethnicity, Predict Breast Self-Examination.

The American Cancer Society has recommended monthly breast self-examinations (BSEs) to aid in the early detection of breast cancer. Compliance with BSE recommendations has been shown to be decreased in certain ethnic groups. This investigation evaluates relevant variables involved in BSE compliance in an urban breast cancer screening center. A survey over a 1-year period (June 1996-June 1997) was given to all patients on their initial visit to the Breast Health Center at Tulane University Medical Center. Demographic and socioeconomic factors associated with the compliance of BSE were explored. The overall rate of BSE was relatively high at 80%. There was no difference between ethnic groups in rates of BSE (Caucasians 21% versus African Americans 20%). Statistically significant variables associated with BSE noncompliance were high school education (did not complete high school 16% versus completed high school 33%; p < 0.0004), employment status (employed 16% versus unemployed 31%; p < 0.0004), and marital status (married 15% versus single/divorced 22%; p < 0.05). While the majority of women in our study practiced BSE and ethnicity did not predict BSE, several socioeconomic factors were predictive of BSE compliance. Efforts to increase community outreach to lower socioeconomic patients as well as efforts to ensure proficient BSE techniques by patients may help detect early breast cancer.