Tick-Bites in Sheep Causing Mortality

            Lamb mortality in Norway is on the rise with a mortality rate of 30% threating the lamb industry. However predation is not a factor in the death of lambs. Researchers from Bioforsk suspect tick-bites are the cause of lamb mortality infecting 300,000 lambs a year. Tick-bites in lambs result in tick-borne fever (TBF) and is a result of the bacterium Anaplasma phaagocytophilum (A.ph). This bacterium causes fever and weakens the immune system. In humans, the bacteria can cause flu like symptoms and decrease the immune system resulting in pneumonia in many cases. The disease is not fatal in either humans or lambs, but arthritis is common after lambs have been infected. Lambs are more susceptible to secondary infections after being infected with A.ph and the majority of deaths are a result of acute pasteurella infections. The bacterial infection causes blood poisoning and inflammation of the heart, heart sac, lungs and digestive organs. Vaccinations are available for acute pasteurella infections and are recommended for lambs that are in areas of high tick-borne fever.

            Research is currently underway to develop measures that help sheep tolerate tick-bites better. Although, researchers know lambs respond to infections differently. It has been discovered some lambs experience shorter fever or a shorter period with a decreased immune system. Research is also being conducted on the number of ticks lambs have and how this correlates to the growth of lambs. There is also on-going research on long-term acaricides used to kill mites and ticks; lambs are still being infected despite the use of acaricides. More research needs to be conducted that focuses on prevention of tick bites and how to control tick populations to decrease the occurrence of tick bites in lambs.   

By Anette Tjomsland

References

Bioforsk-Norwegian Institute for Agricultural and Environmental Research (2013, November 12). Ticks kill sheep. Sciencedaily. Retrieved November 14, 2013, from http://www.sciencedaily.com-/releases/2013/11/131112091015.htm

http://www.bioforsk.no/ikbViewer/page/en/article?p_document_id=106704 

The Discovery Of a New factor That Promotes Breast Cancer

            Breast cancer is the second most commonly diagnosed cancer in women; the estrogen-receptor positive breast cancer (ER+ breast cancer) is the most common type. Researchers determined estrogen to promote tumor growth in ER+ breast cancer; patients with ER+ breast cancer would undergo endocrine-base therapies. The therapies consisted of depleting tumors of estrogen, therefore inhibiting the growth of tumors. However, these therapies have been unsuccessful in many patients diagnosed with ER+ breast cancer. Research conducted by Wu et al. has discovered another promoter of tumor growth in ER+ breast cancer, the cholesterol metabolite 27-hydroxycholesterol (27HC). This could also be an explanation of why endocrine-base therapies have been unsuccessful in several cases.

            The research conducted by Wu et al. examined patients with ER+ breast cancer. The results displayed in tumor tissue 27HC content were more abundant than in normal breast tissue. The increase of 27HC content in tumors was a result of the decreased expression of CYP7B1, an enzyme that metabolizes 27HC. The enzyme, CYP7B1 not being able to break down 27HC leads to the increase of 27HC and can be connected with ER+ breast cancer. The prognosis of ER+ breast cancer is dependent on CYP7B1, and the suppression is linked with mortality in cancer patients.

            There are factors that can cause the increase of 27HC such as, women that undergo menopause. The increase of 27HC may be related to the decrease of estrogen that postmenopausal women experience. It has been discovered that estrogen helps regulate CYP7B1 and decreases the 27HC content. Other factors that increase 27HC are obesity, hypercholesterolemia and dyslipidermia also referred to as high-fat and high-cholesterol in the body. High-fat diets and obesity increase the risk of breast cancer and obesity displayed an increase in tumor growth. The results displayed these factors as being promoters for ER+ breast cancer.

            The significance of the research is the ability to find new therapies that revolve around decreasing 27HC content or increasing the metabolizing enzyme CYP7B1. The research allows healthcare providers to determine a prognosis based on CYP7B1 levels in the body. More research needs to be conduct to determine prevention and treatment of ER+ breast cancer.

By UT Southwestern Medical Center

Dr. Philip Shaul and his team were the first to determine that 27HC promotes tumor growth in breast cancer. 

 References

Qian Wu, Tomonori Ishikawa, Rosa Sirianni, Hao Tang, Jeffrey G. McDonald, Ivan S. Yuhanna, Bonne Thompson, Luc Girard, Chieko Mineo, Rolf A. Brekken, Michihisa Umetani, David M. Euhus, Yang Xie, Philip W. Shaul. 27-Hydroxycholesterol Promotes Cell-Autonomous, ER-Positive Breast Cancer Growth. Cell Reports, 2013; DOI:10.1016/j.celrep.2013.10.006

UT Southwestern Medical Center (2013, November 7). Researchers discover new driver of breast cancer. ScienceDaily. Retrieved November 9, 2013, from http://www.sciencedaily.com/releases/2013/11/131107122744.htm

Dogs Can Express Emotions

Dog owners like to consider their dogs as children, and say they know when their dog is happy or upset. The research article by Siniscalchi et al. has determined dog’s emotions by tail wagging. Dogs wagging to the right displayed positive emotions and wagging to the left displayed negative emotions. Dog owners can now really known when their dog is happy or upset.

            The research by Siniscalchi et al. has determined that dogs like other vertebrates, such as humans exhibit asymmetrically organized brains. This means left brain activation produced tail wagging to the right and right brain activation produced left tail wagging. The experiment was to introduce dogs of various breeds to naturalistic and silhouette moving video images. The stimulus displayed dogs with no wags and wagging to the left and to the right. When the left tail wagging stimulus was introduced, the dogs heart rate increased and appeared to be more stressed and anxious. When the right tail wagging stimulus was introduced, the dogs appeared to be more relaxed and natural. The research has indicated that right hemisphere activation is associated with negative responses and left hemisphere activation is associated with positive responses. The research has also indicated tail wagging could be a way of communication for dogs as a signal for danger.

Zeke experiencing left tail wagging and appears to be more stressed and anxious 

References 

Cell Press (2013, October 31). Dogs known a left-sided wag from a right. ScienceDaily. Retrieved November 2, 2013, from http://www.sciencedaily.com­/releases/2013/10/131031124916.htm

Siniscalchi et al. Seeing left or right asymmetric trail wagging produces different emotional responses in dogs. Current Biology, 2013 DOI: 10.1016/j.cub.2013.09.027