« PreviousNext »Global Heart Volume 6, Issue 4 , Pages 201-210, December 2011. Youth Manifesto on Non - Communicable Diseases . Sandeep P. Kishore: Affiliations. Weill Cornell Medical College, New York, NY, USA; These authors contributed equally to this work. ...

Natural genetic variation in reproduction and life history strategies is a manifestation of variation in underlying regulatory neuronal and endocrine systems. A test of the hypothesis that genetic variation in luteinizing hormone (LH) level could be related to a life history trait, seasonal reproduction, was conducted on artificial selection lines from a wild-source population of white-footed mice (Peromyscus leucopus). Variation exists in the degree of suppression of reproduction by winter short-day photoperiods (SD) in wild-source individuals and in the laboratory population. In this population, most individuals from a photoperiod-responsive (R) artificial selection line are strongly suppressed reproductively in SD, while most individuals from a photoperiod-nonresponsive (NR) artificial selection line are only weakly reproductively suppressed in SD. We assayed levels of LH to test for genetic variation between lines that could contribute to variation in reproductive status in SD. Females from both lines were raised in long-day photoperiods (LD) or SD, ovariectomized under isoflurane anesthesia, and given estradiol implants. Levels of LH were significantly higher in the NR line than in the R line, indicating genetic variation for levels of LH. Levels of LH were higher in LD than in SD, indicating that levels of LH were sensitive to photoperiod treatment even with a controlled level of estradiol negative feedback. The results indicate that there is genetic variation in levels of LH that could be functionally important both in the laboratory in SD and in the wild population in winter. Thus genetic variation in levels of LH is a plausible causal factor determining winter reproductive phenotype in the wild population.

Recent advances in immunology have provided a foundation of knowledge to understand many of the intricacies involved in manipulating the human response to fight parasitic infections, and a great deal has been learned from malaria vaccine efforts regarding strategies for developing parasite vaccines. There has been some encouraging progress in the development of a Chagas vaccine in animal models. A prize fund for Chagas could be instrumental in ensuring that these efforts are translated into products that benefit patients.

Human Papillomavirus (HPV) is a major cause of morbidity and mortality worldwide, with most of the disease burden concentrated in developing countries. Over 90 percent of cervical cancer deaths, almost all of which are caused by HPV, occur in low- and middle-income countries where access to goods and services for prevention and treatment pose major barriers to intervention. In resource-poor settings lacking the capacity for routine screening for cervical cancer, the HPV vaccines developed by Merck and GlaxoSmithKline are desperately needed to help prevent these unnecessary deaths. The initial development of currently available HPV vaccines took place at a number of universities and other publicly funded institutions, yet there is little low-cost access to the vaccine in developing countries where access would be most critical. This is the rule rather than the exception with most university-discovered medicines. Universities and other publicly-funded institutions can adopt a number of licensing methods to ensure that vaccines discovered on their campuses are available at low-cost in developing countries. Universities Allied for Essential Medicines has proposed that universities adopt Global Access Licensing policies to implement these changes by enabling generic or low-cost production of the end product in developing countries. Generic competition is a critical market force that has, for instance, driven down the price of HIV/AIDS treatments from more than $10,000 to less than $99 per patient per year today. While the central barrier to creation of small molecule generics is patent-protection, there are multiple additional barriers that need to be addressed in order to ensure the efficient production of cost-effective generic vaccines and other biologics. While certain biologics may require generic producers to perform additional clinical trials, vaccines are in a somewhat unique situation with respect to both safety and efficacy. With access to appropriate patents, materials and knowledge, vaccines have the potential to be evaluated efficiently and cost-effectively via a pathway parallel to establishing bioequivalence for generic small molecule drugs. A new paradigm is needed that addresses the additional barriers that exist, outside of simply patent protection, to the generic production of vaccines and other biologics. One possible framework, which builds upon previous work on prize funds and patent pools, is discussed here: a Patents, Materials, and Know-how Pool (PMK Pool), based on the patent pool model such as those outlined in the Essential Medical Inventions Licensing Agency and proposals recently put forth by the governments of Barbados and Bolivia. University approaches to licensing vaccines and other biologics need to ensure access not only to patents, knowledge, and materials covered by intellectual property, but must also address the problem of access to materials and know-how that are often proprietary trade secrets. Universities should actively participate in the creation of this and other novel mechanisms, and in the meantime use currently available technology transfer mechanisms to ensure low-cost access to medicines in developing countries.

BACKGROUND:Responsiveness to changing photoperiods from summer to winter seasons is an important but variable physiological trait in most temperate-zone mammals. Variation may be due to disorders of melatonin secretion or excretion, or to differences in physiological responses to similar patterns of melatonin secretion and excretion. One potential cause of nonphotoresponsiveness is a failure to secrete or metabolize melatonin in a pattern that reflects photoperiod length.

METHODS:This study was performed to test whether a strongly photoresponsive rat strain (F344) and strongly nonphotoresponsive rat strain (HSD) have similar circadian urinary excretion profiles of the major metabolite of melatonin, 6-sulfatoxymelatonin (aMT6s), in long-day (L:D 16:8) and short-day (L:D 8:16) photoperiods. The question of whether young male HSD rats would have reproductive responses to constant dark or to supplemental melatonin injections was also tested. Urinary 24-hour aMT6s profiles were measured under L:D 8:16 and L:D 16:8 in young male laboratory rats of a strain known to be reproductively responsive to the short-day photoperiod (F344) and another known to be nonresponsive (HSD).

RESULTS:Both strains exhibited nocturnal rises and diurnal falls in aMT6s excretion during both photoperiods, and the duration of the both strains' nocturnal rise was longer in short photoperiod treatments. In other experiments, young HSD rats failed to suppress reproduction or reduce body weight in response to either constant dark or twice-daily supplemental melatonin injections.

CONCLUSION:The results suggest that HSD rats may be nonphotoresponsive because their reproductive system and regulatory system for body mass are unresponsive to melatonin.