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Do You Know What You’re Putting on Your Baby?

Your baby’s skin is smooth, soft, and highly delicate. “A baby’s skin is thinner and has less hair, so it’s more fragile than yours,” says Pamela Jakubowicz, MD, dermatologist at Montefiore Medical Center and assistant clinical professor at Albert Einstein College of Medicine.  So how you care for your baby’s skin is very important. Here are some guidelines for keeping your baby’s skin healthy.

If your child has sensitive skin:

  • Steer clear of products that have fragrances and perfumes.  
  • Avoid dryer sheets or fabric softeners, which leave a film on clothing and can irritate tender infant skin. 
  • Stay away from shampoo or washes made with sodium lauryl sulfate, which tend to burn children's eyes. 

If your infant gets cradle cap, a build-up of scales on the scalp, apply a little mineral oil to the scalp and gently brush away the thick scales with a very soft-bristle brush or toothbrush, suggests Jakubowicz.

Soaps and Anti-Bacterial Products

Avoid deodorant soaps meant for adults, they are harsh and too drying on a baby's skin. Although they may not lather as well, try milder liquid or bar products that will be labeled “cleansing bar” or “skin cleanser.” “Babies aren’t sweating, you don’t have to use anything harsh to get its skin clean,” says Jakubowicz.

Avoid using anti-bacterial products. They tend to dry out a baby's gentle skin. Also, regular use of anti-bacterial household products may actually increase the possibility that the germs they are meant to kill will eventually become more resistant to these products, and harder to kill.

Although bubble bath products may make bath time more fun for children, they tend to dry skin out. Be sure to use a bubble bath that is mild enough for frequent use. Using a moisturizer after bathing can also help avoid dry skin.

Moisturizers and Sun Protection

Stick to creams, ointment, and emollient moisturizers instead of lotions. “If it comes in a tube, it’s usually more effective,” says Jakubowicz. Avoid products that list alcohol in the ingredients. Alcohol tends to produce a drying effect that's counterproductive to moisturizing.

Try to keep babies less than six months old out of the sun, or dress them in sun-protective clothing. When that’s impossible, apply a small amount of sunscreen with at least 15 SPF to exposed areas like the face and back of hands. For older babies, choose a sunscreen labeled “broad-spectrum” with an SPF of at least 15, and reapply every two hours or after swimming or sweating. Look for physical sunscreens and sunblockers or chemical-free sunscreen products that contain zinc oxide or titanium dioxide.

Protect Baby's Tender Bottom

If your baby develops a diaper rash, make sure to change your baby’s diaper every three to four hours, and immediately after a bowel movement. Wipes can be irritating to raw skin, so use unscented wipes or a soft cloth with water until it heals. Allow baby’s bottom to air dry. A cream or ointment with zinc oxide can help protect the area. For prevention, petroleum ointments should do fine.

For the first three months, or longer, if your baby has sensitive skin, avoid baby wipes that have fragrances. You can also skip the wipes altogether and just use wash cloths and a squirt bottle of water at the baby's changing table.

When diapering your baby, avoid talcum powder, which has been linked to breathing problems if your baby inhales the powder. “If you really want to use it, apply it to the diaper away from the baby to reduce the chances that a cloud of powder will be inhaled,” says Paul Horowitz, MD a pediatrician at Discovery Pediatrics in Valencia, Calif.

日期:2011年7月2日 - 来自[Parenting]栏目
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16 Signs You‘re Too Strict With Your Kids

If your 4-year-old gets sassy at the dinner table, do you wash her mouth out with soap, give her a time-out, or take away a prized position? What about your fifth grader who is not doing well in school and refuses to do his homework -- do you take away his television or video privileges? And what do you do when your teen starts missing curfew?

Discipline dilemmas plague all parents. How can you tell if you are taking your discipline techniques too far or not far enough?

That classic parenting dilemma is at the heart of controversy about Amy Chua's memoir, The Battle Hymn of the Tiger Mother.

In the book, Chua calls her eldest daughter “garbage” for being disrespectful in front of guests, throws away a homemade birthday card because it wasn’t up to snuff, bans sleepovers, and refuses to except anything other than straight A’s from her two daughters.

That's left many parents wondering if they are too strict, or perhaps too lenient, with their own children -- and what effect it will have on their children when they grow up.

“In America, we tend not to be strict enough and everyone wants to be friends with kids,” says Elizabeth J. Short, PhD, a psychology professor and the associate director of the Schubert Center at Case Western Reserve University in Cleveland.

But being too strict is risky because it could undermine the kids.

“They are eager to please and worried about parental approval, so you end up with kids that are anxious and indecisive,” Short says. “Or sometimes they know there is no way they can hit the bar you have set, so they don’t even try.”

Here are 16 signs that you are too strict with your kids, and what you can do about it.

1. You set too many rules.

“It is a sign that you are too strict for everyone’s good if you set so many rules that you can’t possibly enforce them all,” says Nancy Darling, PhD, a psychology professor at Oberlin College in Oberlin, Ohio. Instead, set fewer rules and reinforce them very consistently. “Follow-through is really important," Darling says.

2. Your threats are over the top.

“Saying ‘I am going to destroy all your toys’ or ‘throw you out of the house’ won’t work because if your kid says ‘fine’, all you can do is back down,” Darling says. “What you have done is make an empty threat, and taught your child to misbehave,” she says. “It’s a problem when you can’t back down and know that you have made a mistake because you don’t even believe in what you are doing anymore.”

3. Your rules overstep your parental boundaries.

“Parents can and should set rules about how a child does in school, treats other people, and safety issues,” Darling says. Rules about safety and moral issues are OK, but rules about personal issues (for example, what instrument the child should take up) may not be appropriate, she says.

It is not always so black and white, because parents and kids don't always agree about which issues are personal and which are related to safety or morals. “Sometimes what the parents say is about safety or morality, kids say is personal,” Darling says. For instance, music with violent or demeaning lyrics may strike parents as something to set rules about to avoid bad influences, but their teens may say it's just their personal taste.

“Say, ‘I always love you, but I expect you to behave in this way' or, 'I know you can do better,'” Darling says. "Don’t say, ‘You are garbage if you don’t behave in this way.'" The latter is attacking your child’s core.

5. You don’t watch your words.

It’s not just how you say it; it is what you say. Even if your tone is measured, your words matter.

“Calm voices can say mean things,” Darling says. “Content is more important than the way it is said."

6. You don’t put in the time.

When you do ask your child to do something difficult, work alongside them instead of ordering them to do it. “Good parenting is about putting the time in,” Darling says.

7. You are always the cop, nag, monitor, or reminder.

If these are the mainstays of your relationship to the exclusion of many other things that one could and should do as a parent, you may be too strict,” says Ron Taffel, PhD, a New York-based child psychologist and the author of several books on parenting, including Childhood Unbound.

8. Your child leaves you out.

If your child talks to you less and less about the things that matter, this could be a sign that you are too strict,” Taffel says. “You can win the battle, but lose the war. ... You can get your child to do things that you like them to do, but they are not opening up to you about the things that make them anxious or uneasy.”

9. Your children don’t bring their friends over anymore.

“Kids want rules and all kids will gravitate to a house with rules, but if you spend your time reminding children about the rules, criticizing your child in front of other kids, and asking too many probing questions, your kids may stop bringing their friends by,” Taffel says. “If children do ask for return play dates, and other kids talk to you and approach you, you have made your house a home that kids want to be in.”

10. Your child is seen, not heard.

"In the 21st century -- with kids Twittering, tweeting and Facebooking everything -- they expect to be heard,” Taffel says. “You are too strict if you don’t give kids two or three minutes in the spotlight a day to state their opinion,” he says. “You don’t have to agree with them or do what they are saying, but you should allow them the time to say it.”

11. Your child is all work and no play.

“Kids need comfort time and downtime to synthesize what they have learned,” Taffel says. “If they are filled with skills, knowledge, and information that they can’t use and are just learning for the sake of learning, their brains end up like sponges absorbing things, but they have no idea what it all means."

“Find out what other parents are doing,” Taffel says. “When no other parents are doing the same exact thing as you such as not allowing your children to go online even with parental supervision, you may be too strict."

13. You forbid anything.

You don’t encourage something, but you also don’t forbid it,” Short says. "Say, ‘I'd rather you didn’t do this for these reasons, but if you choose to do it anyway, I may keep a closer watch on you because of my concerns.’”

14. If the rules are the rules, no questions asked.

“You have to have rules in place, so your children know they can be broken,” Short says. “There have to be clear, consistent rules because it helps with predictability and expectations, but there also needs to be some wiggle room in special situations.” For example, if your child has a midnight curfew but the designated driver is drunk, they need to feel comfortable phoning home to ask for leniency and a ride, she says.

15. If you are authoritarian, not authoritative.

There’s a difference, Short says. Authoritative parents set clear expectations and can be hard on their kids, but they do it out of warmness and concern for a child’s betterment whereas authoritarian parents say "It’s my way or the highway." Authoritarian parents are "controlling and not warm," Strong says. "An authoritative parent is age-appropriately controlling and also warm."

16. You are as cold as ice.

“Nobody cares if parents are tough as long as they are warm,” Short says. “It’s when you are tough and cold that is really the problem."

日期:2011年2月4日 - 来自[Parenting]栏目

How to Know You’re in Love? Brain Scans Tell All

Jan. 4, 2011 -- Romantic love lights up the same brain regions of lovers, whether they’re heterosexual or homosexual or male or female, a new study indicates.

Pictures from functional magnetic resonance imaging scans (fMRIs) show similar activity in cortical and sub-cortical brain regions when lovers, regardless of gender or sexual orientation, see images of their romantic partners, according to researchers at University College London.

These regions are known to be rich in dopaminergic activity. And dopamine, the scientists point out, is the so-called “feel good” neurotransmitter.

Serotonin is thought to be important in regulating emotional relationships as well as in bonding between individuals.

Brain Regions Light Up

Semir Zeki, a professor in the University College London’s Wellcome Trust Center for Neuroimaging, and John Romaya, a senior programmer, scanned the brains of 24 volunteers as they viewed pictures of their romantic partners.

The participants also looked at pictures of friends of the same sex as their lovers, but to whom they were not attracted.

While some brain regions showed increased activity when lovers viewed images of romantic partners, others shut down, such as parts of the temporal, parietal, and frontal cortex, which are thought to be important in judgment.

That finding lends credence to the adage that “love is blind,” says Zeki.

Half of the volunteers were males, half females, and six of each sex were homosexual and the other six heterosexual. And all told the researchers they were passionately in love with their partners.

The participants ranged in age from 19 to 47, and relationship lengths ranged from four months to 23 years.

All were asked to rate their feelings toward their romantic partners before and again after scanning, and to declare their sexual orientation in groups ranging from exclusively heterosexual to exclusively homosexual.

Visual Impact

“Passionate romantic love is commonly triggered by a visual input and is an all-consuming and disorienting state,” Zeki says in a news release. “Previous studies have demonstrated that despite the complexity of this emotion, the brain patterns triggered when viewing the face of someone you’re in love with are limited to only a few, though richly-connected brain regions.”

Zeki says the study was influenced by a reading of world literature about love, including works by Shakespeare, Plato, and Dante. Their writings describe similar sentiments whether in the context of opposite sex or same sex relationships.

All volunteers provided six to eight picture portraits of their lovers and also portraits of other friends of the same sex about two weeks prior to undergoing their fMRI scans.

The study is published in the journal PLoS One.

Sign up today for WebMD's Sex & Relationships newsletter and get trusted information that will help keep your relationships healthy and balanced.

日期:2011年1月5日 - 来自[Health News]栏目
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If You‘re Pregnant, You Can Eat for Two, Right?

In every issue of WebMD the Magazine, we ask experts to answer readers' questions about a wide range of topics, including some of the oldest -- and most beloved -- medical myths out there. In our July-August 2010 issue, we asked Julie Redfern, RD, LDN, a registered dietitian at Brigham and Women's Hospital in Boston, to weigh in on just how much a pregnant woman should eat.

Q: Now that I'm pregnant, I get to "eat for two," right?

A: While there may be days when you feel so hungry you could eat a horse, the idea that you should "eat for two" is, alas, FALSE.

"That is an old myth," says Julie Redfern, RD, LDN, a registered dietitian at Brigham and Women's Hospital in Boston. "Many women who do 'eat for two' end up gaining an excessive amount of weight."

You certainly should be increasing the amount of certain nutrients. But you need only about 300 more calories per day, Redfern says, about the equivalent of "one slice of whole grain bread and one tablespoon of peanut butter." If you put on too much weight during pregnancy, you increase your risk of gestational diabetes, backaches, high blood pressure, and needing a cesarean birth because your baby is very large.

Conversely, gaining too little weight during pregnancy is a concern. It can lead to low birth weight, premature delivery, and, later, developmental delays, learning disabilities, and chronic health problems in your baby.

Trying to Conceive? Tips to Help You Get Pregnant

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Do you know how your body (and your baby) changes week by week through your pregnancy? Sign up today for the Pregnancy Week by Week newsletter and let us join you on the road to motherhood.

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日期:2010年8月7日 - 来自[Pregnancy]栏目

Kids Not Only Obese, They‘re Extremely Obese

March 18, 2010 -- Extreme obesity has reached ''alarming'' levels among children, according to a new study that looked at the weights and heights of more than 710,000 children aged 2 to 19.

''The prevalence of extreme obesity was much higher than we thought," says the study’s lead author, Corinna Koebnick, PhD, a research scientist at Kaiser Permanente in Southern California, a large prepaid health plan.

''Seven percent of boys and 5% of girls -- that is scary," she tells WebMD. That was the overall prevalence of extreme obesity she found. Before the study findings, Koebnick says, she would have expected perhaps 3% to 5%.

And the 7% and 5% figures are overall. For some ethnic groups, the prevalence of extreme obesity was much higher -- up to nearly 12%.

Extreme Obesity in Children: Study Details

Koebnick and her colleagues looked at electronic medical charts that had the height and weight of more than 700,000 children who had inpatient and outpatient visits in 2007 and 2008.

The sample studied was gender-balanced, with 357,205 boys and 353,744 girls.

They classified them as overweight, obese, or extremely obese.

Overweight is defined as the 85th or higher percentile on the growth charts, according to guidelines from the CDC. Obese is defined as the 95th percentile or higher.

"Extreme obesity is defined as 120% of the 95th percentile for weight for age and sex," Koebnick says.

In simpler terms, Koebnick says, ''For a 10-year-old boy or girl, you would expect him or her to weigh about 70 pounds." If the child weighs 140 pounds, that would be extreme obesity, she says.

''This is the first study using the new CDC definition of extreme obesity," she says.

Extreme Obesity in Children: Findings

Koebnick's team found:

  • 37.1% of the children were overweight
  • 19.4% were obese
  • 6.4% were extremely obese

Then they looked at gender and ethnic or racial differences. The prevalence of extreme obesity was highest in Hispanic boys, with as many as 11.2% being extremely obese, and in black girls, with as many as 11.9% of them extremely obese.

The prevalence of extreme obesity peaked at 10 years in boys and at 12 and also 18 in girls, the researchers found.

''This is a serious health issue,'' Koebnick says. ''These children are very likely to continue to be obese adults and face all the health consequences that come with obesity at a very early age.'' That includes heart disease and diabetes, among other ailments, she says.

Extreme Obesity: Second Opinion

The findings of the new study are no surprise to Lisa Goldman Rosas, PhD, postdoctoral fellow in family and community medicine at the University of California San Francisco School of Medicine, who has researched obesity in Hispanic children. The finding of increased obesity among Hispanic and black children has been consistent, she says. “That’s shown in national data, other studies of Kaiser populations,’’ and other research, she says.

日期:2010年3月20日 - 来自[Health News]栏目
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西洋参与糖尿病

    西洋参(Panax quinquefolium L),为五加科人参属植物,俗名美国人参、花旗参、洋参、广东参,原产于北美洲加拿大的蒙特利尔,魁北克和美国东部。药用部分为干燥的根,味苦,性凉,人心、肺、肾经。功能以补益为主,有滋阴生津、凝神益智功效。早在清康熙33年《补图本草备要》和清乾隆30年《本草纲要拾遗》中,已有西洋参药性的记载。我国应用西洋参已有近30G年的历史,20世纪70年代后期,在我国和日本引种栽培成功,此后对西洋参的使用与开发日益广泛深入,产品的种类、数量和质量都在逐年提高。

西洋参对高血压和心肌营养不良、冠心病、心绞痛等有一定疗效。同时,西洋参还可降低化疗放疗治癌肿引起的不良反应,常作为治疗各种癌症的辅助药剂。西洋参还具有多方面的药理活性,具有抗疲劳、强壮体魄、提高机体免疫功能、抗缺氧、抗高温、抗寒、抗心肌缺血、抗休克、降低血脂、镇静、止血等作用。而西洋参用于糖尿病的保健和治疗的报道在我国并未多见,近年来,国外对于西洋参在2型糖尿病的预防治疗方面有一些深入的研究报道,现将近年来国内外有关这方面文献作如下综述。

 1   化学成分

西洋参主要化学成分为皂苷类,其它还含有一些挥发油、多糖类、氨基酸类、聚乙炔类和酶等。

11  皂苷类化合物

    西洋参主要成分为人参皂苷类化合物,迄今为止,从西洋参中获得的人参皂苷分属三个类型:其一母体结构为达玛烷型(Dammarane);其二母体结构为齐墩果烷型(Oleanane);其三为奥克悌隆型(Oeotill01)

    1978年日本真田修一等从日本产的西洋参中分离出人参皂苷R0RblRb2RcRdRe1979年中国学者李向高从中国西洋参根中分得3种皂苷元:人参萜二醇(Panaxadial)、人参萜三醇(Panaxatri01)和齐墩果酸(Oleanolie acid)1983年魏均娴等从西洋参根中分得:R0Rb1Rg1Repseudo—ginsenoside—FII(简称 P—F11)P—Fll是奥克悌隆醇型皂苷,是西洋参中的特有成分,是同属植物人参中所没有的,是鉴别西洋参与人参的显著标志。1985年松浦广道又从西洋参根中分得:Rb1Rb2Rb3RcRdReRoRg1Rg2F2P— F11、绞股兰皂苷一XⅦ(简称Gy—XⅦ)、西洋参皂苷一R1(简称Q—R1)1987年徐绥绪等从西洋参根中分得:R0Rb1Rb2RdReRg1Rg2Rg3Rh1和一种新皂苷,命名为人参皂苷RAo1988年张祟禧等从中国黑龙江西洋参根中分得:R0Rb1Rb2RcRd ReRg1。印度学者Ashok Shgh报道从美国西洋参中发现9种皂苷,其中主要的皂苷为人参皂苷Rb类。Le Men—Olivier L等从法国产西洋参根中提得:Rb1 RdReP— F11Gy—XⅦ1998年周雨等从西洋参中分得丙二酸单酰基人参皂苷一Rbl(简称M—Rb1)Rb1Re1997年李铣等从加拿大西洋参根中分得两个新的齐墩果酸型皂苷,命名为quinquenoside— R3 ,R4(简称Q—R3Q—R4),另外还分得Rb1Rb2 Rb3RcRdReRg1Rg2Rg3Rh120R—Rh21997年王金辉等从加拿大产西洋参根中分离得到2个新化合物,命名为西洋参皂苷L4和西洋参皂苷l2,另外还分得人参皂苷 Rg1ReRdRcRb1Rb2 Rb3和假人参皂苷F11、珠子参苷 F1、绞股蓝皂苷和绞股蓝皂苷XⅦ1998年又分离得到一种ionol型葡萄糖苷---linafionoside A2000年丛登立等从西洋参叶中分离得到人参皂苷Rh1Rh2Rh32003年苏健等又从吉林产西洋参的根中分离得到10个皂苷单体,分别是24(R)一假人参皂苷RT524(R)一假人参皂苷 F11,人参皂苷Rg1Rg3ReRdRcRb1Rb2和三七皂苷 K2006年郭娜等从加拿大西洋参根中分离到8个皂苷类化合物,分别是Rg8Rg6F1Rh120(R)Rh1 Rg2ReRb1,其中Rg8为首次得到。江海鹏等于2006年也在西洋参根中分离到8个皂苷类化合物, GimenosideⅢMajoroside—F1为首次分离得到,其余是Rg1Rg220(R)Rg2RdReRb1.

    12  挥发油类

沈宁等从吉林栽培的西洋参挥发油中用GC— MS法鉴定出37种化合物,并测定了各成分的相对含量,其中倍半萜类化合物有26种,约占总挥发油75%,为西洋参中挥发物的主要成分。郑友兰等对黑龙江栽培的西洋参中挥发油成分进行了分离与鉴定,从碱性组分、强酸性组分、弱酸性组分、中性组分挥发油中共分离和鉴定出34种化合物。

13  其它

西洋参另外还含有氨基酸类、糖和多糖类、酶类、具有挥发性和很强的抗白血病细胞(h2v)的细胞毒活性的聚乙炔类化合物。

2  西洋参对糖尿病的作用

    多年来,医药学者对西洋参进行了大量的药理药效研究工作。主要集中在以下几个方面:对于中枢神经系统,具有镇静、增强学习记忆、促进神经生长、抗惊厥、镇痛、解热的作用;②对于心血管系统,具有抗心律失常、抗心肌缺血和再灌损伤等的作用;③对于血液系统,具有抗溶血、止血、降低血液凝固性、抑制血小板凝聚、调血脂、抗动脉粥样硬化、降血糖等的作用;@对于适应原样作用,具有抗疲劳、抗缺氧缺血、抗休克、抗饥渴、抗高低温和各种化学因素;对于免疫系统,具有降过氧化脂质以及丙二醛、增强SOD活力、抑制淋巴细胞转化、脾重等的作用;对于内分泌系统,作用于垂体一肾上腺皮质系统(ACTH)和垂体性腺系统、促进血清蛋白合成、促进骨髓蛋白合成、促进器官蛋白合成、促进脑内蛋白合成和脂肪合成、促进肝细胞蛋白(RNA聚合酶活力)合成、促进脂肪代谢和糖干弋谢等作用;对于泌尿系统,具有捌尿作用;对于肿瘤和病毒,具有抑制癌细胞增殖、抑祺单纯疱疹等病毒的作用,关于以上这些作用在这里就不再重述,重点进行对糖尿病的作用综述。   

当今世界,糖尿病已经成了人类健康的主要随题,美国加州大学洛杉矶分校地理及环境健康科学教授戴蒙德在《自然》杂志发表的研究结果显示,目前全球15亿患上2型糖尿病(或称成人糖尿病),世界范围内这一发病概率在3%左右,但发病率在各地不一:欧洲人只有2%患此病,在美国约有占总人口5%的人患有糖尿病,而非裔美国人患此病者有13%,中南美裔美国人有17%,美国土著则有50%。我国在京、沪、港和穗等大城市的成年人群中,其发病率已经接近或愈10%,我国已成为仅次于印度的第2位糖尿病大国。而糖尿病患者当中,90%为2型糖尿病患者。对于糖尿病的治疗,传统药物,尤其是在2型糖尿病的治疗上,一些植物提取物起到了良好的作用,其中的代表药物人参类已经在临床上应用多年,动物的体内实验也已经证明亚洲人参、西洋参具有降糖活性。西洋参对于糖尿病的活性研究报道多见于国外文献,国内鲜有报道。

21  药理研究

    John Zeqi Luo等研究结果表明,西洋参具有调节人体葡萄糖达到动态平衡的作用,由于西洋参对糖尿病的治疗作用机制还不清楚,从而限制了西洋参的应用。一般认为,大多数糖尿病的病因是由于胰腺p细胞分泌胰岛素的功能被破坏所致。最近一种线粒体蛋白拆分蛋白一2(UCP2)被发现,它在胰岛素的合成和β细胞的存活中起到很关键的作用,初步研究发现,西洋参提取物可以抑制UCP2的表达,保护β细胞,提高胰岛素的合成能力,由此提出西洋参对糖尿病作用机制假说,即西洋参提取物能够抑制胰腺β细胞线粒体中的UCP2的活性,提高胰岛素合成能力和抗细胞凋亡。为验证这一假说,实验中将β细胞与含白介素和不含白介素的西洋参提取物水溶液在去血清中静态培养24h,以此来评价西洋参对于UCP2的表达、胰岛素的产生、抗细胞凋亡因子Bcl2的表达、促细胞凋亡因子caspase9的表达,以及细胞的 ATP水平的影响。研究发现,西洋参能够抑制UCP2、下调caspase9,同时增加ATP的产生和胰岛素的分泌,并且上调Bcl2,减少细胞凋亡。这些发现提示,西洋参提取物能够通过抑制线粒体UCP2的活性来刺激胰岛素的产生、预防β细胞的流失,结果导致 ATP水平的提高,抗细胞凋亡因子Bcl2的增加,同时下调促细胞凋亡因子caspase9,从而降低细胞凋亡的发生,这些结果充分支持了以上的假说。

    Hasegawa H等对西洋参的有效成分RblRg的研究中发现,人参皂苷在通常情况下具有促进葡萄糖转移的功能,人参皂苷Rbl在最低lmmotL的浓度条件下就可以增加(24±5)的葡萄糖转移生理活性,人参皂苷Pg3也表现出对诱导抑制绵羊红细胞运转葡萄糖的重要作用。Yokozawa T等人研究发现,人参皂苷 Rb2可以激活模型大鼠的脂质代谢和糖代谢。

22  临床研究

    由于糖尿病发病率居高不下,而且有加速上升的趋势,使得西方国家尤其是美国进一步加大了对糖尿病的研究力度。2型糖尿病是一种临床慢性复杂疾病,不仅仅是血糖异常升高,而且常常伴随着高血压、高血脂等等一系列心血管系统的各种疾病,据统计,2型糖尿病人的死亡有75%与其并发的心血管系统疾病有关,所以,在这一类疾病的治疗上往往比较复杂,在降糖的同时有时还要降血压、降血脂,控制饮食、限制吸烟等等。由于这些常规治疗方法并不能彻底解决问题,从经济能力方面考虑,食品补充剂和植物药的应用数量急剧上升,同时也相应开展了相关临床实验研究。

    近年来,VLADIlVflR VUKSAN博士等人在西洋参餐后降糖的研究中作了大量的临床研究工作,主要采取的方法是随机、双盲、多个体交叉设计、安慰剂对照,剂量依赖性研究、时间依赖性研究等。为验证西洋参的降血糖的作用,进行了一组4中心实验,lO名非糖尿病受试者,92型糖尿病受试者,分别给与3g西洋参胶囊或安慰剂胶囊(玉米面)40min后各自口服25g葡萄糖进行干预,分别在服用葡萄糖15min30min45min~60min90min120min时间点采集血样,-20℃低温保存,3d内完成血糖测试分析,并进行统计学处理,结果显示,西洋参对于两组受试者都表现出了削弱餐后血糖过多的作用。

    研究人员对西洋参作用于2型糖尿病的剂量和时间的关系进行如下实验研究,lO2型糖尿病人(4名男性、6名女性),按计划方案分别在口服25g葡萄糖之前120min80min,40min,0min给与安慰剂胶囊(玉米面)3g~6g9g西洋参胶囊,在分别于口服葡萄糖后0min15min30min60min,90min、和120min时间点采取血样,进行血糖测试分析,结果表明,3g6g9g三个剂量没有差异性,在2h内也没有相关性。另一组实验是在12名健康受试者中进行随机交叉设计实验,剂量梯度为0g(安慰剂)1g2g3g西洋参,西洋参服用时间为在口服25g葡萄糖之前40min20min10min~0min,采血样时间点为口服葡萄糖后0min15min30min60min90min,血糖指标分析测试结果表明,西洋参降低非糖尿病人餐后血糖的作用具有时间依赖性而不具有剂量依赖性,西洋参的活性在葡萄糖干预后40min内具有时间相关性,在1—3g剂量范围内表现出相同的疗效。

    作为从食品补充剂的角度来调理2型糖尿病人的血糖,西洋参已经应用多年了,但西洋参降糖的药效物质基础尚未完全阐明,各类人参皂苷在心血管方面的活性研究较多,在对糖尿病治疗的作用机理方面还应该做进一步的深入探讨,由于西洋参提取物作为复合成分对糖尿病做了较为深入的机理探讨,阐明了西洋参提取物能够通过抑制线粒体UCP-2的活性来刺激胰岛素的产生、预防β细胞的流失,提高ATP水平,使抗细胞凋亡因子Bd-2增加,同时下调促细胞凋亡因子caspase9,降低细胞凋亡的发生,从而改善2型糖尿病患者的血糖水平,现在我们所面临的任务是要研究西洋参提取物中到底是那些成分在发挥作用,希望通过对西洋参提取物中大量化学成分的筛选研究,发现一些对糖尿病人血糖调节作用明确的化合物或化合物组合,为今后血糖调节药物的开发提供新的机会。

日期:2010年1月14日 - 来自[药物与临床]栏目

高效液相色谱法测定双参龙胶囊中人参皂苷 Re含量的研究

  【摘要】   目的建立以高效液相色谱法测定双参龙胶囊中人参皂苷 Re含量的方法,改进原含量测定方法。方法色谱柱为supelcosiltmlC18,流动相为乙腈-0.1%磷酸溶液进行梯度洗脱,检测波长为203 nm ,流速为1.0 ml/min ,柱温为室温,进样量为10 μl 。结果人参皂苷Re进样量在0.45~4.5 μg范围内与峰面积积分值线性关系良好(r=0.999 1),平均回收率为96.81 %(RSD =1.08%) 。结论 该方法简便、快捷、专属性强、重现性好,克服了原薄层扫描法背景干扰较大、重复性较差等缺陷,可用于双参龙胶囊的质量控制。

  【关键词】  高效液相色谱法 双参龙胶囊 人参皂苷 Re

  Abstract:ObjectiveTo establish an HPLC method for the content determination of gingsenoside Re in Shuangshenlong capsule, improve the original method of TLCS. MethodsHPLC was performed on supelcosiltmlC18 column at room temperature,the mobile phase consisted of acetonitrile - 0.1% phosphoric acid solution with gradient elution,the detection wavelength was 203 nm with flow rate 1.0 ml / min and sample size 10 μl. ResultsGinsenoside Re was linear with the peak area in the range of 0.45~4.5 μg(r2=0.999 1),the average recovery was 96.81 %(RSD =1.08%).ConclusionThe established method is simple,reliable, reproducible, and it improves the shortcomings of the strong background interference and the bad repetibility ect. It can be used for the quality control of  Shuangshenlong capsule.

  Key words:HPLC ;  Shuangshenlong capsule;  Gingsenoside Re

  双参龙胶囊是国家药品监督管理局颁布的国家药品标准品种,其标准[标准编号:WS-10218(ZD-0218)-2002]对方中西洋参的人参皂苷 Re(C48H82O18)进行了含量测定,但其采用的是薄层扫描(TLCS)法,背景干扰较大,重复性较差。而2005版《中国药典》[1]西洋参中人参皂苷 Re采用的是高效液相色谱(HPLC)法,为此我们对其进行了改进,拟采用HPLC法测定其含量。

  1  仪器与试药

  1.1  仪器

  Shimadzu LC 2010高效液相色谱仪,CLASS-VPVER6数据处理软件。PE-λ16紫外分光光度仪;ES-110S电子分析天平(Start Rius,精确到0.001)。

  1.2  试药

  双参龙胶囊(购自青海省格拉丹东药业有限公司);人参皂苷 Re(中国生物制品检定所);其它试剂均为分析纯。

  2  方法与结果

  2.1  色谱条件色谱柱:supelcosiltmlC18 ( 25 mm×4.6 mm,5 μm )。流动相[1,2]:以乙腈为流动相A,以0.1%磷酸溶液为流动相B,按表1中的规定进行梯度洗脱;检测波长为203 nm;流速1.0 ml/min。理论塔板数按人参皂苷Re峰计算应不低于5 000。

  2.2  检测波长的选择取人参皂苷Re对照品溶液,照分光光度法[1],在200~500 nm波长范围内进行扫描,结果人参皂苷Re在203 nm波长处有最大吸收,可作为HPLC法测定双参龙胶囊中人参皂苷Re含量的检测波长。紫外扫描图谱见图1。

  2.3  供试品溶液制备方法的选择[3,4]

  2.3.1  取本品50粒,取内容物,精密称定,研细,取10 g,精密称定,置具塞锥形瓶中,精密加甲醇50 ml,称定重量,加热回流1 h,立即冷却,再称定重量,用甲醇补足减失的重量,摇匀,用干燥滤纸滤过,弃去初滤液,精密量取续滤液25 ml,蒸干,残渣加水40 ml使溶解。用乙醚振摇提取3次,30 ml/次,弃去乙醚液,水液用水饱和的正丁醇振摇提取4次(30,30,30,20 ml),合并正丁醇液,用1%碳酸氢钠溶液洗涤4次(30,30,30,20 ml),弃去碱液,正丁醇液用正丁醇饱和的水洗涤4次(30,30,30,20 ml),分取正丁醇液,蒸干,残渣用甲醇适量溶解,转移至25 ml具塞瓶中,蒸干,精密加入2ml甲醇使溶解,摇匀,即得。表1  梯度洗脱表(略)

  2.3.2  取本品50粒,取内容物,精密称定,研细,混匀,取约10 g,精密称定,置索氏提取器中,加乙醚100 ml,加热回流提取1 h,弃去乙醚液。药渣挥去乙醚,置具塞锥形瓶中,精密加入水饱和的正丁醇100 ml,称定重量,加热回流1.5 h,放冷,再称定重量,用水饱和的正丁醇补足减失的重量,摇匀,滤过。精密量取续滤液50 ml,置蒸发皿中,蒸干,残渣加50%甲醇适量使溶解,并转移至10 ml量瓶中,加50%甲醇至刻度,摇匀,滤过,取续滤液,即得。

  实验结果表明,采用方法“2.3.1”项下方法制成的供试品溶液含有较多油脂,进样后杂质峰较多,基线不平。采用“2.3.2”项下方法制成的供试品溶液杂质少,分离效果好,故选择“2.3.2”项下方法进行供试品溶液的制备。

  2.4  对照品溶液的制备取经五氧化二磷干燥约3 h至恒重的人参皂苷 Re对照品适量,加甲醇制成每毫升含0.22 g的溶液,即得。

  2.5  线性关系考查精密吸取浓度为225 μg /ml的人参皂苷Re对照品溶液2,5,10,15,20 μl注入液相色谱仪,测定其峰面积积分值,以进样量为横坐标,峰面积积分值为纵坐标,绘制标准曲线,其回归方程为:Y=263 862X+4 890.6,r=0.999 1。结果表明人参皂苷Re在0.45~4.5 μg范围内具有良好的线性关系。数据见表2,标准曲线图见图2。表2  线性关系考查结果(略)

  2.6  精密度实验精密吸取同一供试品溶液10μl,重复进样5次,测定其峰面积积分值。结果见表3。表3  精密度实验结果(略)

  结果表明:本方法精密度较好。

  2.7   稳定性实验精密吸取同一供试品溶液10 μl,分别于0,4,8,12,16,20 h进样,测定其峰面积积分值。结果见表4。表4  稳定性实验结果(略)

  结果表明,供试品溶液在20 h内峰面积值基本稳定。

  2.8   重复性实验取同一批号(批号:050704)供试品5份,依法测定,结果见表5。表5  重复性实验结果(略)

  结果表明,本方法重复性较好。

  2.9   回收率实验取已知含量为0.037 4%(批号050704)的样品约5.5 g,共5份,精密称定,分别精密加入人参皂苷Re对照品溶液(225 μg/ml)10 ml,即2.25 mg,按含量测定项下的方法测定含量,结果见表6。表6  回收率测定结果(略)

  结果表明,本方法加样回收率较高。

  2.10  样品测定结果精密吸取对照品溶液与供试品溶液各10 μl,注入液相色谱仪,在选定条件下,人参皂苷Re峰与样品中其它组分色谱峰可达基线分离,按人参皂苷Re峰计算,理论塔板数在5 000以上,阴性样品、对照品、供试品色谱图分别见图3~5。按质量标准正文中的含量测定方法测定3批样品中人参皂苷Re含量。结果见表7。表7  3批样品的人参皂苷Re含量测定结果(略)

  结果表明,3批样品中人参皂苷Re平均含量为211 μg/粒。原胶囊中人参皂苷Re含量限度为30 μg/粒,考虑到原标准含量限度较低,国家药品监督管理局对国家药品标准(试行)颁布件有关说明中建议:积累含量数据,制订合理限度。综合考虑,将双参龙胶囊的人参皂苷Re的含量限度定为不得低于150 μg/粒,高于原标准。

  3 讨论

  研究和提高药物的质量标准一直是药物质量研究领域尤其是中药质量标准研究领域的重大课题,中国对于中药质量的研究也一直在不断地提高和深入。本研究参照《中国药典》[1]西洋参含量测定项下的方法,对双参龙胶囊中人参皂苷 Re的含量方法进行了研究,将原标准中的薄层扫描法改为高效液相色谱法,克服了原方法背景干扰较大,重复性较差的缺点。

  根据国家药品监督管理局对国家药品标准(试行)颁布件的有关建议,我们通过对3批样品的含量测定结果,制订了更合理的含量限度。将原胶囊中人参皂苷Re含量限度30 μg/粒,提高到150 μg/粒,远远高于原标准,从而增加了标准对于双参龙胶囊质量的可控性。

  2005版《中国药典》[1]西洋参中人参皂苷 Re的高效液相色谱含量测定方法中,采用的是梯度洗脱法,我们将该条件应用到双参龙胶囊中人参皂苷 Re的含量测定中,并选择了供试品溶液的处理方法,结果样品分离效果好,从而消除了干扰。

  【参考文献】

  [1]国家药典委员会.中国药典,Ⅰ部[S].北京:化学工业出版社,2005:87.

  [2]陈军辉,谢明勇,王慧琴,等.西洋参中人参皂苷类HPLC测定及其指纹图谱研究[J].食品科学,2005,26(11):200.

  [3]郑虎占,董泽宏,佘 靖.中药现代研究与应用[M].北京:学苑出版社,1997:19.

  [4]陈军辉,谢明勇,章志明,等.12种西洋参中总皂苷及人参皂苷Rb1的测定比较[J].时珍国医国药,2005,16(9):845.

 

日期:2009年11月7日 - 来自[色谱论文]栏目
循环ads

人参茎叶皂苷中人参皂苷Re含量的反相高效液相色谱测定方法的改进

  【摘要】目的改进高效液相色谱法测定人参茎叶皂苷中人参皂苷Re的方法。方法最佳色谱条件:ODS(150 mm×4.6 mm,5μm)为色谱柱,采用梯度洗脱(乙腈与水),检测波长203 nm,流速1.0 ml/min。结果人参皂苷Re的回归方程为Y=9 505.448 8X-1 159.607 0,r=0.999 8,线性范围为1.88 ~60.16 μg/ml,平均回收率为99.35% (RSD=0.49%,n=6)。结论采用改进的测定方法简单、准确和重现性好,适合人参茎叶皂苷中人参皂苷Re的质量控制。

  【关键词】  人参茎叶皂苷; 人参茎叶皂苷Re; 反相高效液相色谱

  Abstract:ObjectiveTo improve the HPLC method for determination of ginsenosid Re in ginsenosides. MethodsODS column(150 mm×4.6 mm,5 μm) was used. The mobile phase consisted of CH3CN-H2O, the detection wavelength was 203 nm,and the flow rate was 1.0 ml/min.ResultsThe regression equation of  ginsenoside Re was Y=9 505.448 8X-1 159.607 0 with a correlation coefficient of 0.999 8,and linear range was within the range of 1.88 ~60.16 μg/ml, the average recovery of ginsenosid Re was  99.35% (RSD=0.49%,n=6). ConclusionThis method is simple, quick, and reproducible and it is suitable for the quality control of Panax ginseng.

  Key words:Panax ginseng;  Ginsenosid Re;  RP-HPLC

  人参茎叶皂苷是从五加科植物人参的干燥茎叶中提取的有效成分经喷雾干燥而得,其中含有各种苷如人参皂苷Re。关于人参皂苷中人参皂苷Re的测定方法已有文献报道[1~4],笔者也曾采用PR-HPLC法对人参茎叶皂苷中的人参皂苷Re的含量进行了测定,但有些样品中人参皂苷Re存在分离不完全的情况。为了准确地测定人参皂苷Re的含量,我们对该方法进行了改进和研究,采用梯度方法对人参皂苷Re的含量进行了测定。现报道如下。

  1   仪器与试药

  岛津LC-2010A高效液相色谱仪(LC-10AD泵,SPD-M10AVP检测器,SIL-10VP自动进样器,Class-VP色谱工作站);超声波清洗器(CSX-370,上海医用恒温设备厂);电子分析天平(岛津公司)。

  人参皂苷Re标准品,批号110754-200421,供含量测定用,中国药品生物制品检定所提供;甲醇为分析纯(广州市化学试剂公司),乙腈为色谱级(MERCK),水为重蒸水。人参茎叶皂苷粉由陕西禾博天然产物有限公司提供。

  2  方法与结果

  2.1    色谱条件Shim-pack VP-ODS分析柱(150 mm×4.6 mm,5 μm);流动相为乙腈-水;流速1.0 ml/min;检测波长203 nm;柱温:35℃;梯度条件见表1。

  表1  流动相的梯度洗脱(略)

  在上述色谱条件下,人参皂苷Re与杂质完全分离,人参皂苷Re的保留时间约17 min(图1~3),理论塔板数按人参皂苷Re峰计算大于2 500。

  图1  空白溶液高效液相色谱图(略)

  图2  人参皂苷Re对照品溶液高效液相色谱图(略)

  图3  样品溶液高效液相色谱图(略)

  2.2  对照品溶液的制备精密称取人参皂苷Re对照品5 mg(真空干燥至恒重)置25 ml量瓶中,加少量甲醇,超声溶解30 min,待溶液恢复常温后,用甲醇稀释至刻度,用0.22 μm的微孔滤膜过滤溶液备用。

  2.3  线性关系考察精密吸取上述人参皂苷Re对照品溶液,分别进样0.25,0.50,1.0,2.0,4.0,8.0 μl,按上述色谱条件测定峰面积。以人参皂苷Re对照品进样量为横坐标,色谱峰面积为纵坐标,绘制标准曲线。经线性回归,人参皂苷Re的回归方程为:Y=9 505.448 8X-1 159.607 0,r=0.999 8,在1.88~60.16 μg/ml范围内线性关系良好。

  2.4  精密度实验对含人参皂苷Re低、中、高3种浓度的标准溶液,于同日内分别测定6次,并对上述3种浓度的标准溶液于不同天分别测定6次。结果见表2。

  2.5  稳定性实验吸取同一供试样品溶液分别于0,4,6,8h及第1,2,4天后分别测定结果RSD分别为0.63%,1.13%,表明该样品溶液3 d内稳定。

  2.6  重复性实验取同一批号样品(20070401批号),照“2.2”项下方法制备6份,分别测定,计算RSD为0.52%。

  表2  日内及日间差异实验结果(略)

  2.7  加样回收率实验采用加样回收法。分别精密称取已测知含量的样品(含量人参皂苷Re12.2%)约10 mg ,共计6份,每2份为1组,每组分别加入18.80 μg/ml的人参皂苷Re对照品1,5,10 ml,精密加甲醇至50 ml,密塞、超声提取30 min,放冷,用甲醇补足失重,用0.22 μm滤膜过滤,测定实际含量,计算回收率,结果见表3。

  表3  回收率实验结果(略)

  2.8  供试品溶液的制备取(20070401批号)样品,按“2.2”项下供试品溶液的制备方法,以人参皂苷Re含量为优选指标,分别超声处理15,30,45 min。结果表明超声处理30 min为最佳提取时间。

  取供试品约10 mg,精密称定,至25 ml量瓶中加甲醇,超声溶解30 min,待溶液恢复常温后,加甲醇稀释至刻度,摇匀,用0.22 μm滤膜过滤,即得。

  2.9  样品测定按“2.2”项的方法进行处理3批样品,照上述色谱条件,反复进样6次。结果见表4。

  表4  样品含量测定结果(略)

  3  讨论

  为了提高分离效能,本实验采用梯度洗脱的方法。流动相比例的确定:在上述色谱条件下,本实验对流动相A 相、B 相分别选择了不同比例的甲醇与水(磷酸溶液)、乙腈与水和多种梯度条件进行试验。结果证明,流动相选择乙腈与水进行梯度洗脱,人参皂苷Re与杂质分离效果最好。

  该方法灵敏、准确可靠,可以作为人参茎叶皂苷中人参皂苷Re的含量测定方法。

  【参考文献】

  [1] 候团章.中草药提取物(第1卷)[M].北京:中国医药科技出版社,2004:106.

  [2] 苗明三.现代实用中药质量控制技术[M].北京:人民卫生出版社,2000:29.

  [3] 国家药典委员会.中国药典,Ⅰ部[S].北京:化学工业出版社,2005:7.

  [4] 许海琴,许列琴.常用天然提取物质量标准参考手册[M].北京:化学工业出版社,2003:108.

 

日期:2009年10月13日 - 来自[色谱论文]栏目
共 5 页,当前第 1 页 9 1 2 3 4 5 :

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