السلام عليكم

مو قلبهم طيب.. بس بيلغولهم كل البحث إذا ما قالوا هيك مشان جميعة حقوق الحيوان......

بس عنجد ملفت للنظر كيف الدكاترة بكلية الصيدلة عندهم أبحاث واكتشافات... طب ليش كمان دكاترتنا ما بيعملوا هيك كمان؟؟؟ ويتسجل شي بحث باسمهم وينشر بالمجلات العالمية..... 

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High Amounts of the Hormone Leptin Are Linked to Decreased Depression


Newswise — Women who have higher levels of the appetite-controlling hormone leptin have fewer symptoms of depression, and this apparent inverse relationship is not related to body mass index (BMI), a new study finds. On Monday the results will be presented at The Endocrine Society’s 93rd Annual Meeting in Boston.

“Animal data suggest that leptin may reduce anxiety and improve depression. Our study in women suggests that leptin may indeed have antidepressant qualities,” said the study’s lead author, Elizabeth Lawson, MD, of Massachusetts General Hospital and Harvard Medical School in Boston.

Leptin, the product of fat cells, signals satiety, or fullness. It is low in thin women and high in obese women, according to Lawson. She also said there is an increased prevalence of anxiety and depression in certain conditions in which leptin levels are typically low. These include the eating disorder anorexia nervosa, in which there is abnormally low weight and body fat, and functional hypothalamic amenorrhea, in which women have stopped menstruating despite having normal weight.

“It is unknown whether low leptin levels contribute to the development of mood disorders in these women,” Lawson said.

She and her co-workers studied the relationship between leptin levels and symptoms of anxiety and depression in 64 women. Fifteen of the women had anorexia nervosa, 12 were normal weight with hypothalamic amenorrhea, 20 were normal weight and in good health, and 17 were overweight or obese but still healthy.

All subjects were asked questions to assess symptoms of depression and anxiety, with high scores indicating more symptoms. Besides measuring leptin levels in the blood, the researchers assessed the women’s BMI, a measure of weight for height.

They found that higher leptin levels were linked to decreased symptoms of anxiety and depression. The relationship between leptin and depression symptoms was independent of BMI. This finding indicates that leptin may mediate symptoms of depression and that this effect is not a function of low weight, Lawson said.

“Further research administering leptin to humans will be important in understanding whether this hormone has a potential role in the treatment of depression,” she said.

The current study received funding from Bioenvision in New York City and from the National Institutes of Health

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Drug Shows Promise in Prostate Cancer Spread to Bone


Bone scans show tumor shrinkage after Cabozantinib; bone pain reduced

Newswise — ANN ARBOR, Mich. — A new drug to treat prostate cancer shows early promise, particularly against tumors that have spread to the bone, a multi-site study shows.

The drug Cabozantinib is designed to target mainly two important pathways linked to the growth and spread of prostate cancer. The drug had the most effect on tumors that had spread to the bone.

“Not only did three-quarters of bone scans have partial or complete resolution, but this was accompanied by improvement in bone pain and decreased need for narcotic use,” says lead study author Maha Hussain, M.D., FACP, professor of internal medicine and urology and associate director of clinical research at the University Michigan Comprehensive Cancer Center.

Hussain presented the findings at the American Society of Clinical Oncology annual meeting.

The trial enrolled 171 men with metastatic prostate cancer. In more than three-quarters of the men enrolled, cancer had spread to the bone.

Researchers found 76 percent of patients saw some or all of their tumor shrink on bone scans following treatment with Cabozantinib. In addition, among patients who were on narcotics due to bone pain, 67 percent reported less pain and 56 percent either stopped taking narcotics or reduced the dosage. In addition, more than two-thirds of patients had some tumor regressions in areas of spread outside the bone. The treatment effects lasted on average 29 weeks.

The study found moderate side effects from Cabozantinib, including fatigue, gastrointestinal symptoms and high blood pressure.

“What’s interesting about this drug is it brings to the table something we haven’t seen before. Dramatic improvements in bone scans are unprecedented in this disease. Despite measurable progress, current treatment options for advanced prostate cancer tend to be modest in effect, so adding to and improving these options is a high priority,” Hussain says.

Hussain cautions that this is very early data, but it opens a new door for further investigation. The manufacturer, Exelixis, has developed a randomized clinical trial that is currently open at the U-M Comprehensive Cancer Center and other locations. For information, call the U-M Cancer AnswerLine at 800-865-1125

السلام عليكم


دواء جديد يجعل القلب يصلح بنفسه أضرار الأزمات القلبية   


لندن-سانا

نجح علماء بريطانيون في استخدام دواء يجعل القلب يصلح بنفسه الأضرار التي تلحق به إثر

الإصابة بأزمة قلبية بعدما كان الاعتقاد السائد هو أن الضرر الذي يصيب القلب نتيجة هذه

الأزمات هو ضرر دائم.

وذكرت هيئة الإذاعة البريطانية بي بي سي أن دراسة نشرت في مجلة نيتشر الطبية أظهرت

أن استخدام دواء ثايموسين بيتا 4 قبل حدوث الأزمة القلبية يمكنه أن يحفز القلب على إصلاح

نفسه.

واكتشف الباحثون من جامعة لندن مجموعة من الخلايا موجودة في جدار القلب لكنها تصبح

خاملة عند البالغين ويمكنها التحول إلى أنواع أخرى من الخلايا في الاجنة وباستخدام الدواء

تتحول الى خلايا عضلة القلب ما يجعل القلب يضخ الدم بشكل أفضل ويصبح جداره أكثر

تماسكاً.

إلا أن الباحثين حذروا من أن التحسن الذي يحدث لدى الحيوانات خلال التجارب غالباً ما يكون أكبر

مما يحدث عند البشر مشيرين إلى أنه إذا تم التوصل إلى دواء يحدث الأثر نفسه عند البشر

فقد يوصف لمن تحتمل إصابتهم بأزمات قلبية إما نتيجة معرفة تاريخ عائلي للمرض أو تقدير

الطبيب لإشارات إمكانية الإصابة.

وقال البروفيسور بول رايلي من الجامعة لمسنا تحسناً في قدرة القلب على ضخ الدم بنسبة

25بالمئة مشيرا الى انه بالإضافة إلى ذلك تقلص الندب الموجود في النسيج نتيجة التعرض

لأزمة قلبية كما أن جدران القلب زادت سماكة.

السلام عليكم:

Apples Help Keep Muscles Strong, Mouse Study Finds


Discovery may lead to new treatments to prevent wasting due to aging, illness, researchers say

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B Vitamins in Mother’s Diet Reduce Colorectal Cancer Risk in Offspring


Newswise — Mice born to mothers who are fed a diet supplemented with B vitamins are less likely to develop intestinal tumors, report scientists at the Jean Mayer USDA Human Nutrition Research Center on Aging (USDA HNRCA) at Tufts University.

Previous research in humans and mice suggests that B vitamins, particularly folate, play a role in the prevention of colorectal cancer. Using a mouse model of naturally occurring colorectal cancer, the USDA HNRCA scientists examined whether a mothers’ B vitamin intake impacts her offspring’s cancer risk. Mothers were fed diets containing supplemental, adequate or mildly deficient quantities of vitamins B2, B6, B12 and folate prior to conception through weaning after which all of the offspring received the same adequate diet.

“We saw, by far, the fewest intestinal tumors in the offspring of mothers consuming the supplemented diet,” says Jimmy Crott, PhD, senior author and a scientist in the Vitamins and Carcinogenesis Laboratory at the USDA HNRCA. “Although the tumor incidence was similar between offspring of deficient and adequate mothers, 54% of tumors in the deficient offspring were advanced and had invaded surrounding tissue while only 18% of tumors in the offspring of adequate mothers displayed these aggressive properties.”

The results were published online June 9 in the journal Gut.

Crott and colleagues associated the tumor suppression seen in the offspring of supplemented mothers with a protection against disruptions to the Wnt signaling pathway, a network of genes commonly altered in colorectal cancer.

“The strongest expression of tumor-suppressing genes in the Wnt pathway was in the offspring of supplemented mothers and the weakest was in the offspring of the mildly deficient mothers,” says first author Eric Ciappio, a PhD candidate at the Friedman School of Nutrition Science and Policy at Tufts.

“We attribute these differences in gene expression to epigenetics, modifications of DNA which are sensitive to environmental factors such as diet,” Ciappio continues. “In this case, changing maternal B vitamin intake had lasting epigenetic effects in offspring and may explain the differences in tumor incidence and aggressiveness we observed."

It remains unclear whether maternal consumption of the four B vitamins could impact tumor development in humans. ““While evidence is beginning to accumulate to suggest that maternal consumption of supplements containing folate may afford some protection against childhood cancers in offspring, we don’t yet have the ability to determine whether the same holds true for cancers that normally present in the mid to late decades of life,” explains Crott, who is also an assistant professor at the Friedman School.

Crott adds, “Aside from the known protective effect of maternal folate against neural tube defects such as spina bifida, our results suggest that mothers consuming supplemental quantities of these B vitamins may also be protecting her children against colorectal cancer.”

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هرمون بيولوجي لعلاج قصر القامة   

واشنطن-سانا

قال علماء أمريكيون إنهم طوروا هرمونا لعلاج قصر القامة القزامة يتم تعديله بيولوجيا وحقنه مرة

كل أسبوع خلافاً للهرمونات الحالية التي يتم حقنها يومياً .

ونقلت الدراسة التي نشرت في مجلة بروسيدينجز التابعة للأكاديمية الأمريكية للعلوم عن

الباحثين قولهم إنهم غيروا البرنامج الداخلي للهرمون بحيث لا يتحلل داخل الجسم بسرعة

وكذلك لا يتخلص الجسم منه بسرعة عبر عملية الإخراج مشيرين الى أن التجارب الأولية التي

أجريت على الهرمون المعدل أثبتت أنه فعال ومقبول من الجسم .

ويصنع الهرمون المعروف بهرمون النمو البشري المستخدم في علاج القزامة بشكل بيولوجي

بالفعل حيث يتم إدخال المعلومات الوراثية المسؤولة عن تصنيع البروتين في نوع من البكتيريا

التي تستخدم هذه المعلومات في إنتاج الهرمون .

وقام فريق من الباحثين بتعديل البنية الجينية للبروتين بحيث يتم تبديل إحدى وحدات الأحماض

الأمينية داخله بوحدة أخرى غير موجودة في البيئة يسميها العلماء اختصاراً اسم بي ايه سي

إف ثم يقوم العلماء بإلصاق هذا الحمض الأميني بجزيء بولي اثيلين بي إيه جي يستخدم فيما

يعرف بفترة عمر النصف للمواد الفعالة في الجسم .

ولا يعرف الباحثون على وجه الدقة كيفية حدوث ذلك ولكنهم وجدوا أنه في هذه الحالة يظل

جزيء بي إيه جي فترة أطول في الجسم .

وقد اختبر الباحثون هذا الهرمون المحسن في الخلايا أولاً وعلى الفئران ثم حقنوا به 22 مريضاً

مصاباً بنقص هرمون النمو في أولى تجاربهم الميدانية وذلك مرة كل أسبوع فتبين لهم أنه

يحدث نفس التأثير الذي تحدثه الهرمونات الحالية التي تحقن يومياً وأن المرضى يتحملون هذا

الهرمون بشكل جيد إجمالاً .

وأكد الباحثون أنهم قاموا بالفعل بتحسين الهرمون بشكل يسمح بإخضاعه لدراسات أوسع

وبإنتاجه بشكل صناعي.

السلام عليكم


باحثين سويسريين يكتشف الالية المسببة لفقدان الانسولين فعاليته في الجسم


تمكن فريق من الباحثين بالمعهد الاتحادي السويسري للتقنية في زيورخ اليوم الاثنين من

اكتشاف الالية المسؤولة عن فقدان (الانسولين) لفعاليته في الجسم والتقليل من امتصاص

(الغلوكوز) في الخلايا ما يفتح الامل مجددا في التوصل الى سبل علاج جديدة لمقاومة ارتفاع

نسبة السكر في الجسم.

وقال بيان صادر عن المعهد ان فريق البحث العلمي للبروفسور ماركوس شتوفل بمعهد الانظمة

الحيوية الجزيئية تمكن من رصد ارتفاع نسبة اثنين من الجزيئيات المكونة للحمض الريبي النووي

(ار.ان.ايه) يحملان الرقمين 103 و 107 لدى فئران التجارب المصابة بالسمنة.

وبين انه كلما ارتفعت مستويات هذين الجزيئيين في الحمض الريبي النووي اصبحت خلايا الكبد

والنسيج الدهني اكثر مقاومة للانسولين ولا تتعامل بالمعدلات المطلوبة مع نسبة السكر في

الجسم ما يؤدي الى ارتفاع تركيزها بنسب خطيرة.

وتكمن اهمية هذا الاكتشاف في التغلب على صعوبة التمييز مختبريا بين (ار.ان.ايه 107) و

(ار.ان.ايه 103) حيث استطاع الفريق العلمي التعرف عليهما بدقة متناهية ومتابعة اليات

عملها.

كما اكتشف العلماء دور هذين الجزيئيين في تعطيل عمل المورثة المسؤولة عن انتاج بروتين

(كافيولين1) الذي ينشط عمل المجسات الحساسة لاستقبال اشارات الانسولين الى خلايا

الكبد.

وتمكن العلماء من توقيف عمل كل من (ار.ان.ايه) 107 و 103 فوجدوا ان الخلايا بدأت في

استقبال اشارات الانسولين مجددا واستعادت الية التعامل مع (الغلوكوز) فانخفضت نسبة

السكر في الدم وعاد انتاج الانسولين بوتيرته الطبيعية الى الجسم حسبما اوضحت نتائج

التجارب المجربة على الفئران.

وقال البروفسور شتوفل "ان هذه التجارب تمثل بارقة امل في مكافحة الاصابة بارتفاع معدلات

السكر في الجسم بل يمكن ان تفتح بابا جديدا للتعامل مع هذا المرض من منظور مختلف تماما

عما هو متبع حاليا".

واضاف "ان الطريق الى تصنيع عقار سيحتاج وقتا طويلا لكنه ممكن لاسيما بعد عثور العلماء

على بدايات هذا الطريق فضلا عن اهمية التعاون في هذه المرحلة مع احدى شركات تصنيع

الادوية".

وذكر العلماء السويسريون ان الخلايا الدهنية وخلايا الكبد مجسات كيمائية حساسة تستشعر

اشارات الانسولين الذي ما ان يقترب من تلك المجسات حتى تبدأ الخلايا في امتصاص الغلوكوز

وتخزينه.

الا ان خلايا كبد المصابين بالسمنة تفقد فعاليتها في التفاعل مع تلك الاشارات ولا تتمكن من

استيعاب الاشارات الكيميائية التي يبعث بها الانسولين ومن ثم تفرز خلايا البنكرياس كميات

هائلة وغير محسوبة من الانسولين حتى تصبح منهكة فلا يمكن بعدها السيطرة على نسبة

السكر في الجسم.

سيريالايف

السلام عليكم


Nanoparticles Disguised as Red Blood Cells To Fight Cancer

Newswise — Researchers at the University of California, San Diego have developed a novel method of disguising nanoparticles as red blood cells, which will enable them to evade the body’s immune system and deliver cancer-fighting drugs straight to a tumor. Their research was published this week in the online Early Edition of the Proceedings of the National Academy of Sciences.

The method involves collecting the membrane from a red blood cell and wrapping it like a powerful camouflaging cloak around a biodegradable polymer nanoparticle stuffed with a cocktail of small molecule drugs. Nanoparticles are less than 100 nanometers in size, about the same size as a virus.

“This is the first work that combines the natural cell membrane with a synthetic nanoparticle for drug delivery applications.” said Liangfang Zhang, a nanoeningeering professor at the UC San Diego Jacobs School of Engineering and Moores UCSD Cancer Center. “This nanoparticle platform will have little risk of immune response.”

Researchers have been working for years on developing drug delivery systems that mimic the body’s natural behavior for more effective drug delivery. That means creating vehicles such as nanoparticles that can live and circulate in the body for extended periods without being attacked by the immune system. Red blood cells live in the body for up to 180 days and, as such, are “nature’s long-circulation delivery vehicle,” said Zhang’s student Che-Ming Hu, a UCSD Ph.D. candidate in bioengineering, and first author on the paper.

Stealth nanoparticles are already used successfully in clinical cancer treatment to deliver chemotherapy drugs. They are coated in a synthetic material such as polyethylene glycol that creates a protection layer to suppress the immune system so that the nanoparticle has time to deliver its payload. Zhang said today’s stealth nanoparticle drug delivery vehicles can circulate in the body for hours compared to the minutes a nanoparticle might survive without this special coating.

But in Zhang’s study, nanoparticles coated in the membranes of red blood cells circulated in the bodies of lab mice for nearly two days. The study was funded through a grant from the National Institutes of Health.

A shift towards personalized medicine

Using the body’s own red blood cells marks a significant shift in focus and a major breakthrough in the field of personalized drug delivery research. Trying to mimic the most important properties of a red blood cell in a synthetic coating requires an in-depth biological understanding of how all the proteins and lipids function on the surface of a cell so that you know you are mimicking the right properties. Instead, Zhang’s team is just taking the whole surface membrane from an actual red blood cell.

“We approached this problem from an engineering point of view and bypassed all of this fundamental biology,” said Zhang. “If the red blood cell has such a feature and we know that it has something to do with the membrane -- although we don’t fully understand exactly what is going on at the protein level -- we just take the whole membrane. You put the cloak on the nanoparticle, and the nanoparticle looks like a red blood cell.”

Using nanoparticles to deliver drugs also reduces the hours it takes to slowly drip chemotherapy drug solutions through an intravenous line to just a few minutes for a single injection of nanoparticle drugs. This significantly improves the patient’s experience and compliance with the therapeutic plan. The breakthrough could lead to more personalized drug delivery wherein a small sample of a patient’s own blood could produce enough of the essential membrane to disguise the nanoparticle, reducing the risk of immune response to almost nothing.

Zhang said one of the next steps is to develop an approach for large-scale manufacturing of these biomimetic nanoparticles for clinical use, which will be done through funding from the National Science Foundation. Researchers will also add a targeting molecule to the membrane that will enable the particle to seek and bind to cancer cells, and integrate the team’s technology for loading drugs into the nanoparticle core so that multiple drugs can be delivered at the same time.

Zhang said being able to deliver multiple drugs in a single nanoparticle is important because cancer cells can develop a resistance to drugs delivered individually. By combining them, and giving the nanoparticle the ability to target cancer cells, the whole cocktail can be dropped like a bomb from within the cancer cell.

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Intensive-Dose Statin Therapy Associated with Increased Risk of Diabetes


Newswise — An analysis of data from previously published studies indicates that intensive-dose statin therapy is associated with an increased risk of new-onset diabetes compared with moderate-dose therapy, according to a study in the June 22/29 issue of JAMA.

Compared with placebo, statin therapy significantly reduces cardiovascular events among individuals with and without a history of diabetes mellitus. Recently, findings of several trials comparing intensive- to moderate-dose statin therapy suggested an excess risk of new diabetes among those treated with intensive statin regimens, according to background information in the article. According to the authors, "Given the cardiovascular benefits of statins and the likely increasing use of intensive statin regimens, it is important to quantify any potential long-term risks to enable physicians and patients to make informed choices."

David Preiss, M.R.C.P., of the University of Glasgow, United Kingdom, and colleagues examined the associations of intensive-dose statin therapy vs. moderate-dose therapy with the development of diabetes and the occurrence of major cardiovascular events by conducting a meta-analysis of published and unpublished data from relevant clinical trials. The researchers identified 5 statin trials that met criteria for inclusion in the analysis.

The 5 randomized clinical trials provided data on 32,752 nondiabetic participants over a weighted average follow-up of 4.9 years. During follow-up, 2,749 participants (8.4 percent) developed diabetes (1,449 of whom were assigned intensive-dose therapy, 1,300 assigned moderate-dose therapy), and 6,684 (20.4 percent) experienced a major cardiovascular event (3,134 assigned intensive-dose therapy, 3,550 assigned moderate-dose therapy). There were 149 more cases of incident diabetes in participants assigned to intensive statin treatment than in those receiving moderate therapy and 416 fewer patients with cardiovascular events who received intensive-dose therapy.

An analysis of the data indicated that use of intensive-dose statin therapy compared with moderate-dose statin therapy was associated with a higher incidence of new-onset diabetes. However, intensive statin therapy was associated with fewer major cardiovascular events. As compared with moderate-dose statin therapy, the number needed to harm per year for intensive-dose statin therapy was 498 for new-onset diabetes while the number needed to treat per year for intensive-dose statin therapy was 155 for cardiovascular events.

"Our findings suggest that clinicians should be vigilant for the development of diabetes in patients receiving intensive statin therapy," the authors write. "In conclusion, this meta-analysis extends earlier findings of an increased incidence of diabetes with statin therapy by providing evidence of a dose-dependent association."