Cancer in experimental animals exposed to arsenic and arsenic compounds.

Inorganic arsenic is a ubiquitous environmental contaminant that has long been considered a human carcinogen. Recent studies raise further concern about the metalloid as a major, naturally occurring carcinogen in the environment. However, during this same period it has proven difficult to provide experimental evidence of the carcinogenicity of inorganic arsenic in laboratory animals and, until recently, there was considered to be a lack of clear evidence for carcinogenicity of any arsenical in animals. More recent work with arsenical methylation metabolites and early life exposures to inorganic arsenic has now provided evidence of carcinogenicity in rodents. Given that tens of millions of people worldwide are exposed to potentially unhealthy levels of environmental arsenic, in vivo rodent models of arsenic carcinogenesis are a clear necessity for resolving critical issues, such as mechanisms of action, target tissue specificity, and sensitive subpopulations, and in developing strategies to reduce cancers in exposed human populations. This work reviews the available rodent studies considered relevant to carcinogenic assessment of arsenicals, taking advantage of the most recent review by the International Agency for Research on Cancer (IARC) that has not yet appeared as a full monograph but has been summarized (IARC, 2009 , IARC Special Report: Policy, Vol. 10. Lyon: IARC Press, 453­454). Many valid studies show that arsenic can interact with other carcinogens/agents to enhance oncogenesis, and help elucidate mechanisms, and these too are summarized in this review. Finally, this body of rodent work is discussed in light of its impact on mechanisms and in the context of the persistent argument that arsenic is not carcinogenic in animals.

Effects of alpha- and beta-hydroxy acids on the edemal response induced in female SKH-1 mice by simulated solar light.

alpha- and beta-Hydroxy acids have been used extensively in cosmetic and dermatological formulations. At present, there is an inadequate amount of information with which to assess the safety of topical applications of alpha- and beta-hydroxy acids in conjunction with exposure to ultraviolet light. In the present study, we examined changes in the epidermal basal cell proliferation and the edemal response using skin thickness measurements elicited in SKH-1 mice following exposure to simulated solar light (SSL) with or without topical treatment with creams containing alpha- (glycolic) and beta-hydroxy (salicylic) acids. The dose of SSL light required to induce measurable edema (MED(BIOL)) in nai;ve, free-moving SKH-1 mice was determined to be 90 mJ. CIE/cm(2). Pretreating the mice with daily (5 days/week) exposures of 14 mJ. CIE/cm(2) for 6 weeks resulted in a doubling of the MED(BIOL) to 180 mJ. CIE/cm(2). Topical application of control cream (pH 3.5), or creams containing glycolic acid (10%, pH 3.5) or salicylic acid (4%, pH 3.5) for 6 weeks (5 days/week) increased the MED(BIOL) to 137 mJ. CIE/cm(2). Daily treatments with SSL (14 mJ. CIE/cm(2)) and control cream (pH 3.5), glycolic (10%, pH 3.5) or salicylic (4%, pH 3.5) acid-containing creams for 6 weeks (5 days/week) resulted in an MED(BIOL) value of 180 mJ. CIE/cm(2), which was the same as treatment with light alone for 6 weeks. These data indicate that a 6-week treatment of mouse skin with a representative skin cream, with or without representative alpha- and beta-hydroxy acids (glycolic and salicylic acid, respectively), changes the UV light sensitivity; however, treatment with the cream, with or without the acids, does not contribute to the UV sensitivity of mice cotreated with low doses of UV light.

Whatever happened to eHealth?

Innovations in information technology will continue to transform the health care system to a system that more closely resembles that envisioned in the 1999 and 2001 IOM reports. Healthcare Leadership & Management Report will continue to report over the next few months on practical use of technology to improve the health care system. We are now researching several systems and providers that are using technology to improve their patient care, productivity, bottom line and host of operational concerns.

Malignant pleural effusions.

Malignant pleural effusions contribute to considerable morbidity in cancer patients and generally portend an overall poor prognosis. Treatment of malignant pleural effusions is palliative; therefore, quality of life issues, as well as the risks and benefits of the therapeutic options, become more critical. In my opinion, factors such as in patient versus outpatient management and associated procedural discomfort are important in the decision-making process, and the patient should participate in these subjective considerations. It is difficult to compare results and determine the true efficacy of different techniques and agents because endpoints and response criteria as well as the extent and method of follow-up vary. In addition, the etiology of the primary complaint, dyspnea, is frequently multifactorial. However, malignant effusions recur, and therefore repeated thoracentesis, especially if the fluid rapidly reaccumulates, is usually not a good long-term solution unless the patient's overall prognosis and current condition prohibits a more invasive option. The standard option for recurrent effusions is insertion of a chest tube. If the lung re-expands, chemical pleurodesis is attempted to achieve adherence of the visceral to the parietal pleura. Sterilized talc is the best sclerosant; it has good efficacy and cost effectiveness and can be administered easily as a slurry at the bedside via a chest tube with minimal patient discomfort and without more aggressive and invasive procedures.

Neurogenic tumors of the mediastinum.

Neurogenic tumors can arise from neural cells in any location; however, they commonly are found in the mediastinum and, more specifically, most often are located in the posterior compartment. Neurogenic tumors can be benign or malignant, with a wide array of both clinical and pathologic features that are commonly classified by the cell type of origin. These tumors are usually detected on routine chest radiograph, and a computed tomographic scan is required to obtain more information about involvement of local structures. A magnetic resonance imaging scan may be necessary if a dumbbell-shaped component is identified or suspected. Treatment options vary depending on the presentation, but most often surgical resection is recommended. Whereas patients with benign neurogenic tumors have an excellent prognosis with complete surgical resection, patients with malignant neurogenic tumors still have poor long-term survival prospects.

Useful business and research sites on the Internet.

There are many useful benchmark sites on the Internet for healthcare leaders, and many others that can provide the information healthcare leaders need to do their jobs. During this summer, Healthcare Leadership and Management Report will be redesigning and upgrading its Web site at www.integrated report.com. The new site will contain an extensive list of valuable resources on the Internet for healthcare leaders as well as electronic versions of our issues for subscribers. We welcome our readers to provide us with links that they have found valuable as either resources or as examples of excellent presentation.