Exponential Rise (exponential + rise)

Distribution by Scientific Domains


Selected Abstracts


Tanning and Cutaneous Malignancy

DERMATOLOGIC SURGERY, Issue 4 2008
SHERRIF F. IBRAHIM MD
BACKGROUND Exposure to ultraviolet radiation (UVR) results in a darkening of the skin known as tanning. Recently, it has been shown that tanning is a response to UVR-induced DNA damage and represents the skin's efforts to protect itself against further injury. Despite the link between UVR and cutaneous malignancy, people continue to pursue tanning from natural and artificial sources. This trend is reflected in the exponential rise in skin cancer incidence. OBJECTIVE The objective of this study was to review our current understanding of the factors controlling the tanning response and the relationship to cutaneous carcinogenesis, as well as the impact that the multibillion dollar tanning industry has had on the practice of dermatology. MATERIALS AND METHODS Extensive literature review was conducted in subjects related to tanning and the relationship to cutaneous malignancy. RESULTS Our knowledge of tanning and its effects on the skin has increased tremendously. It is clear that tanning contributes to the development of skin cancer. Despite this information, the incidence of skin cancer continues to increase exponentially. CONCLUSIONS Skin cancer poses a major public health concern and tanning remains the most modifiable risk factor in its etiology. Social, economic, and legislative issues have become tightly intertwined with the complex nature of human behavior in the continued pursuit of an activity that clearly has detrimental effects on one's health. [source]


Counterfeiting in performance- and image-enhancing drugs

DRUG TESTING AND ANALYSIS, Issue 3 2009
Michael R. Graham
Abstract The current drastic escalation in obesity may be contributing to the exponential rise in drugs used for image enhancement. Drugs such as anabolic-androgenic steroids (AAS) are perceived as a viable method of achieving a perfect physique. They are also the most widely abused drugs in sport. The Internet has encouraged the abuse of expensive drugs, particularly human growth hormone (hGH), resulting in increased importation for personal use. The substantial increase in this market has opened up avenues for counterfeiting, estimated as a multi-million pound business. The acute adverse effects from contaminated vials may result in a variety of pathologies including communicable diseases. In 2007, in the UK, a series of intramuscular abscesses, requiring surgical treatment, led us to study samples obtained from the underground market. The analysis of 38 parenteral samples and 19 oral samples of tablets was performed by a World Anti-Doping Agency (WADA) accredited laboratory, in an attempt to establish the extent of available counterfeit products. Fifty-three per cent (20) of the injectable AAS esters and 21% (4) of the oral tablets were counterfeit. Culture and sensitivity revealed the presence of skin commensal organisms, which may have contributed to the development of the abscesses. Users of AAS and hGH for sport, including bodybuilding, are currently risking their health because of counterfeit and poorly controlled products. Copyright © 2009 John Wiley & Sons, Ltd. [source]


TEXTURE PROFILE ANALYSIS , HOW IMPORTANT ARE THE PARAMETERS?

JOURNAL OF TEXTURE STUDIES, Issue 5 2010
ANDREW J. ROSENTHAL
ABSTRACT A starch-glycerol gel was subjected to a two-bite compression test using two sample-instrument geometries, various speeds of compression and strain levels, both with lubrication or not. Results were interpreted using the primary characteristic terminology previously defined in Texture Profile Analysis. Compression speeds from 0.1 to 10 m/s showed a logarithmic relationship with hardness, cohesiveness, corrected cohesiveness and adhesiveness. Gels survived compression to strains of 0.90 without failing, strain levels from 0.25 to 0.90 resulted in an exponential rise in hardness with increasing strain and linear reduction in corrected cohesiveness. Lubrication had no significant influence on any of the measured parameters and an application of force with different sample-instrument geometry revealed that parallel plates and plungers only had an influence on gel hardness. Caution is urged when researchers modify the test protocol from 75% deformation with parallel plates. A minimum crosshead speed of 2 mm/s is recommended. PRACTICAL APPLICATIONS Texture Profile Analysis has been widely applied to test solid and semisolid foods; however, some researchers deviate from the original test protocol. This article attempts to show how modifying the parameters in the test protocol can influence the apparent properties of the sample. [source]


Pattern of maternal circulating CRH in laboratory-housed squirrel and owl monkeys

AMERICAN JOURNAL OF PRIMATOLOGY, Issue 11 2010
M.L. Power
Abstract The anthropoid primate placenta appears to be unique in producing corticotropin-releasing hormone (CRH). Placental CRH is involved in an endocrine circuit key to the production of estrogens during pregnancy. CRH induces cortisol production by the maternal and fetal adrenal glands, leading to further placental CRH production. CRH also stimulates the fetal adrenal glands to produce dehydroepiandrostendione sulfate (DHEAS), which the placenta converts into estrogens. There are at least two patterns of maternal circulating CRH across gestation among anthropoids. Monkeys examined to date (Papio and Callithrix) have an early-to-mid gestational peak of circulating CRH, followed by a steady decline to a plateau level, with a possible rise near parturition. In contrast, humans and great apes have an exponential rise in circulating CRH peaking at parturition. To further document and compare patterns of maternal circulating CRH in anthropoid primates, we collected monthly blood samples from 14 squirrel monkeys (Saimiri boliviensis) and ten owl monkeys (Aotus nancymaae) during pregnancy. CRH immunoreactivity was measured from extracted plasma by using solid-phase radioimmunoassay. Both squirrel and owl monkeys displayed a mid-gestational peak in circulating CRH: days 45,65 of the 152-day gestation for squirrel monkeys (mean±SEM CRH=2,694±276,pg/ml) and days 60,80 of the 133-day gestation for owl monkeys (9,871±974,pg/ml). In squirrel monkeys, circulating CRH declined to 36% of mean peak value by 2 weeks before parturition and then appeared to increase; the best model for circulating CRH over gestation in squirrel monkeys was a cubic function, similar to previous results for baboons and marmosets. In owl monkeys, circulating CRH appeared to reach plateau with no subsequent significant decline approaching parturition, although a cubic function was the best fit. This study provides additional evidence for a mid-gestational peak of maternal circulating CRH in ancestral anthropoids that has been lost in the hominoid lineage. Am. J. Primatol. 72:1004,1012, 2010. © 2010 Wiley-Liss, Inc. [source]


Preliminary evidence that the allogeneic response might trigger antitumour immunity in patients with advanced prostate cancer

BJU INTERNATIONAL, Issue 5 2006
Gordon Muir
OBJECTIVE To explore the possibility that allogeneic responses might, by chance, encompass cross-reactive T cell clones specific for neo-antigenic tumour determinants, and thereby activate antitumour immunity; such cross-reactions are well documented for antiviral immunity, and genetic instability in developing cancers generates many neo-antigenic determinants as potential targets for immune responses, but the biology inevitably favours tumour progression. PATIENTS AND METHODS Fourteen patients with hormone-refractory prostate cancer received full-thickness skin allografts from different, unrelated donors (fellow patients) until each had received six grafts. Serum prostate-specific antigen (PSA) level was used as a surrogate for tumour mass. RESULTS One patient had a remarkable decline in PSA level, with levels at 1 year lower than before grafting. A second patient had stable PSA levels for almost 2 years. A third patient had stable PSA levels for 10,12 months before they resumed an exponential rise. Of four patients with PSA levels of >10 ng/mL, three required surgery or radiotherapy for obstructive symptoms during or shortly after grafting. CONCLUSION Transplant rejection involves mechanistically atypical T cell recognition of allogeneic major histocompatibility complex antigens, with massive polyclonal T cell activation. This unique aspect of T cell biology might represent a novel approach for initiating cross-reactive antitumour responses. [source]