The role of estrogen in cardiovascular disease

Cardiovascular disease is the number one cause of death among women, accounting for nearly 50% of female deaths. Statistics show that women on average develop cardiovascular disease 10 to 15 years later in life than men, and that the risk may increase after menopause. This observation has led to much speculation as to what physiological change(s) associated with menopause is responsible for the higher risk of atherosclerosis. Estrogen, with its potential as a cardioprotective agent and as an immunomodulator of the inflammatory response in atherosclerosis, has received the most attention. Understanding the mechanisms that lead to these differences may allow beneficial therapeutic intervention to enhance this effect in females and evoke this protection in males. This review will do the following: (1) characterize mechanisms of atherosclerosis, (2) explore the role of estrogen-replacement therapy, (3) define the effect of gender on inflammation, (4) compare and contrast the effects of estrogen and testosterone on endothelial functional, and (5) suggest mechanistic based therapeutic opportunities.     

In vivo autofluorescence spectroscopy of oral premalignant and malignant lesions: distortion of fluorescence intensity by submucous fibrosis

BACKGROUND AND OBJECTIVES: To test whether autofluorescence spectroscopy can be used for the diagnosis of oral neoplasia in a high-risk population, we characterized the in vivo autofluorescence spectra from oral submucous fibrosis (OSF) lesions and oral premalignant and malignant lesions in both OSF and non-OSF patients. STUDY DESIGN/MATERIALS AND METHODS: Autofluorescence emission spectra were measured under the excitation wavelength of 330 nm, using a Xenon lamp-based fluorospectrometer coupled to a handheld optical fiber probe. Autofluorescence spectroscopies were analyzed among patients with OSF lesions, and oral lesions of epithelial hyperkeratosis (EH), epithelial dysplasia (ED), and squamous cell carcinomas (SCC) and normal oral mucosa (NOM) of healthy volunteers. RESULTS: We found that the most intensely autofluorescence emission peaks occurred at 380 nm and 460 nm. For comparing the spectral patterns among different groups of oral lesions and NOM, ratios of the area under the spectrum of 460+/-10 nm to that under the spectrum of 380+/-10 nm (denoted as A(460+/-10nm)/A(380+/-10nm)) were calculated. The mean ratio values increased gradually from OSF to NOM, to EH and ED, and to SCC. The ANOVA test showed significant differences in the ratio value among all categories of samples (P<0.01). On the other hand, we found that EH, ED, and SCC lesions on OSF patients had distorted autofluorescence intensity. The mean ratio values of EH, ED, and SCC between non-OSF and OSF patients show significant differences. Furthermore, an ANOVA test showed NOM is not distinguishable from EH and ED lesions on oral fibrotic mucosa (P>0.05). CONCLUSIONS: Autofluorescence spectroscopy can be used to diagnose EH, ED, and SCC lesions in non-OSF patients but not in OSF patients.     

PLS-ANN based classification model for oral submucous fibrosis and oral carcinogenesis

BACKGROUND AND OBJECTIVES: For effective management of oral neoplasia, autofluorescence spectroscopy was conducted on patients with different characteristics of oral lesions in vivo. This study tested the possibility of using a multivariate statistical algorithm to differentiate human oral premalignant and malignant lesions from benign lesions or normal oral mucosa. STUDY DESIGN/MATERIALS AND METHODS: A fiber optics-based fluorospectrometer was used to measure the autofluorescence spectra from healthy volunteers (NOM) and patients with oral lesions of submucous fibrosis (OSF), epithelial hyperkeratosis (EH), epithelial dysplasia (ED), and squamous cell carcinoma (SCC). A partial least-squares and artificial neural network (PLS-ANN) classification algorithm was used to characterize these oral lesions to discriminate premalignant (ED) and malignant (SCC) tissues from "benign" (NOM, OSF, and EH) tissues. RESULTS: The normalized and centerized spectra of the different kinds of samples showed similar but divergent patterns. Our PLS-ANN classification algorithm could differentiate "premalignant and malignant" tissues from "benign" tissues with a sensitivity of 81%, a specificity of 96%, and a positive predictive value of 88%. CONCLUSIONS: We conclude that the PLS-ANN classification algorithm based on autofluorescence spectroscopy at 330-nm excitation is useful for in vivo diagnosis of OSF as well as oral premalignant and malignant lesions.     

Delayed diagnosis of esophageal perforation following intraoperative transesophageal echocardiography during valvular replacement--a case report

A 62 year-old man sustained esophageal perforation following intra-operative transesophageal echocardiography (TEE) in a valvular replacement surgery. Septic shock developed on the 12th postoperative day (POD) and the esophageal perforation was diagnosed with chest CT. Emergent operation together with intensive care saved the patient's life. We speculate that the mechanism of perforation was not due to manipulation of the probe, but rather due to ischemia of the esophagus resulting from the combination of probe compression, non-pulsatile flow and the distension of the atria during a lengthy procedure. It is advisable that in patients with operative risk factors, such as distension of atria, long cardiac procedure and likely ischemia of organs due to cardiopulmonary bypass, the monitoring probe of TEE should not constantly rest in the esophagus and be withdrawn when it is idle or not in actual use. In addition, if resistance has been met during the intraoperative manipulation of the probe in a patient without previous history of esophageal disease, perforation might suspected if he or she sustains postoperative fever with positive chest X-ray findings.     

A novel clinical pattern of visual hallucination after zolpidem use

BACKGROUND: Zolpidem is a new hypnotic that is supposed to have fewer side effects than traditional benzodiazepines. Some psychotic reactions, such as visual or hypnagogic hallucinations, have been reported to be associated with zolpidem use. CASE REPORT: A young female experienced three episodes of hallucination associated with the use of zolpidem. The visual or hypnagogic hallucination happened after she had stopped zolpidem and then restarted it 2 days later. CONCLUSION: We postulate that hypnagogic or visual hallucinations associated with zolpidem use may be related to rapid withdrawal and restarting of zolpidem. The possible mechanism may be associated with the changes in the GABAA receptor. Avoiding "as needed" use of zolpidem and using the lowest effective dose may prevent these adverse effects.     

Noninvasive glucose monitoring by back diffusion via skin: chemical and physical enhancements

Blood glucose levels are routinely obtained by invasive and painful methods using glucose meters and test strips. The development of less invasive or non invasive techniques would be beneficial for diabetes patients. In this study, a noninvasive method was evaluated using the back diffusion of glucose across skin with or without permeation enhancement methods. An in vitro model was utilized. The stratum corneum (SC) was the predominant barrier for both back and forward diffusion of glucose across skin. Surfactants with various charges and essential oils (cyclic monoterpenes) were used as chemical enhancers to promote the back diffusion of glucose. A cationic surfactant (benzalkonium chloride) showed the highest enhancement, followed by anionic and nonionic surfactants. d-Limonene and 1,8-cineole dispersed in appropriate proportions of ethanol could enhance the glucose diffusion after pretreatment of the skin surface. Electroporation, defined as a physical method, significantly increased the amount of glucose that diffused back. The percentages of diffused glucose by 300 V (volts) and 500 V high voltage pulses on skin for 10 min were found to be 45 and 75 times greater than the control group, respectively.