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dijual nih... harga Rp. 4.300.000,- negoAcer Aspire One
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04 April 2009
Role of tumour-associated macrophages in tumour progression
Two different approaches – the use of various transgenic mouse models and the analysis of human tumours – have demonstrated a close link between the activity of tumour-associated macrophages (TAMs) and tumour progression. TAMs are abundant in most forms of solid tumour, where they often display a relatively immature phenotype and are positively correlated with tumour angiogenesis and/or progression .Pollard's group crossed PyMT-MMTV mice (which spontaneously develop mammary tumours) with the transgenic op/op mouse model lacking the gene for colony-stimulating factor-1, a crucial growth factor for macrophages and their precursors from the bone marrow, namely blood monocytes. The tumours that developed in these macrophage-depleted mice showed a slower rate of progression to malignancy and formed far fewer metastases in the lungs than those in non-macrophage-depleted mice. Moreover, Pollard's group recently characterised the development of the vasculature in PyMT-MMTV tumours during progression to malignancy and showed that the onset of the 'angiogenic switch' (the formation of the high-density vessel network associated with the transition to malignancy) was regulated by TAMs. Preinvasive mammary lesions in op/op mice exhibited both a delayed angiogenic switch and transition to malignancy, whereas genetic restoration of the macrophage population in tumours reversed this. Although these studies suggest that TAMs have a key role in promoting tumour angiogenesis, progression to malignancy and metastasis, they have yet to be confirmed in similar studies with other macrophage-depleted, transgenic mouse tumour models.
However, these data accord well with our finding that high numbers of TAMs correlate with increased tumour angiogenesis, lymph node status and reduced survival of breast cancer patients. Moreover, we showed that TAMs in breast carcinomas express numerous tumour-promoting factors such as the important mitogen epidermal growth factor and the pro-angiogenic cytokine vascular endothelial growth factor (VEGF). TAMs have also been shown to release a variety of other cytokines and enzymes known to promote tumour invasion, angiogenesis and metastasis. Recent studies indicate that when macrophages migrate into tumours they downregulate their expression of the potent anti-angiogenic cytokine IL-12 .
These findings have prompted investigations into how the tumour microenvironment 'educates' macrophages to perform these pro-tumour activities. Here we outline the important role of tumour hypoxia in this, both in the form of a direct effect on the expression of pro-tumour genes by TAMs, and indirectly by upregulating the pro-angiogenic cytokine angiopoietin-2 (Ang-2), which in turn has profound effects on TAM function.
dari bebagai sumber
However, these data accord well with our finding that high numbers of TAMs correlate with increased tumour angiogenesis, lymph node status and reduced survival of breast cancer patients. Moreover, we showed that TAMs in breast carcinomas express numerous tumour-promoting factors such as the important mitogen epidermal growth factor and the pro-angiogenic cytokine vascular endothelial growth factor (VEGF). TAMs have also been shown to release a variety of other cytokines and enzymes known to promote tumour invasion, angiogenesis and metastasis. Recent studies indicate that when macrophages migrate into tumours they downregulate their expression of the potent anti-angiogenic cytokine IL-12 .
These findings have prompted investigations into how the tumour microenvironment 'educates' macrophages to perform these pro-tumour activities. Here we outline the important role of tumour hypoxia in this, both in the form of a direct effect on the expression of pro-tumour genes by TAMs, and indirectly by upregulating the pro-angiogenic cytokine angiopoietin-2 (Ang-2), which in turn has profound effects on TAM function.
dari bebagai sumber
Cervical Cancer Overview
The uterine cervix is the lowest portion of a woman's uterus (womb). Most of the uterus lies in the pelvis, but part of the cervix is located in the vagina, where it connects the uterus with the vagina.
Cancer of the cervix occurs when the cells of the cervix change in a way that leads to abnormal growth and invasion of other tissues or organs of the body.
Like all cancers, cancer of the cervix is much more likely to be cured if it is detected early and treated immediately.
One of the key features of cervical cancer is its slow progression from normal cervical tissue, to precancerous (or dysplastic) changes in the tissue, to invasive cancer.
The slow progression through numerous precancerous changes is very important because it provides opportunities for prevention and early detection and treatment.
These opportunities have caused the decline of cervical cancer over the past decades in the United States.
Invasive cancer means that the cancer affects the deeper tissues of the cervix and may have spread to other parts of the body. This spread is called metastasis. Cervical cancers don't always spread, but those that do most often spread to the lungs, the liver, the bladder, the vagina, and/or the rectum.
fr:many resources
Cancer of the cervix occurs when the cells of the cervix change in a way that leads to abnormal growth and invasion of other tissues or organs of the body.
Like all cancers, cancer of the cervix is much more likely to be cured if it is detected early and treated immediately.
One of the key features of cervical cancer is its slow progression from normal cervical tissue, to precancerous (or dysplastic) changes in the tissue, to invasive cancer.
The slow progression through numerous precancerous changes is very important because it provides opportunities for prevention and early detection and treatment.
These opportunities have caused the decline of cervical cancer over the past decades in the United States.
Invasive cancer means that the cancer affects the deeper tissues of the cervix and may have spread to other parts of the body. This spread is called metastasis. Cervical cancers don't always spread, but those that do most often spread to the lungs, the liver, the bladder, the vagina, and/or the rectum.
fr:many resources
Cervical Cancer Causes
Cervical cancer begins with abnormal changes in the cervical tissue. The risk of developing these abnormal changes has been associated with certain factors, including previous infection with human papillomavirus (HPV), early sexual contact, multiple sexual partners, cigarette smoking, and taking oral contraceptives (birth control pills).
Forms of HPV, a virus whose different types cause skin warts, genital warts, and other abnormal skin and body surface disorders, have been shown to lead to many of the changes in cervical cells that may eventually lead to cancer.
Genetic material that comes from certain forms of HPV has been found in cervical tissues that show cancerous or precancerous changes.
In addition, women who have been diagnosed with HPV are more likely to develop a cervical cancer that has genetic material matching the strain of virus that caused the infection.
These findings demonstrate a strong link between the virus and cervical cancer.
Because HPV can be transmitted by sexual contact, early sexual contact and having multiple sexual partners have been identified as strong risk factors for the development of cervical lesions that may progress to cancer.
Cigarette smoking is another risk factor for the development of cervical cancer. The chemicals in cigarette smoke interact with the cells of the cervix, causing precancerous changes that may over time progress to cancer.
Oral contraceptives ("the pill") may increase the risk for cervical cancer, especially in women who use oral contraceptives for longer than 5 years
fr: many sources
Forms of HPV, a virus whose different types cause skin warts, genital warts, and other abnormal skin and body surface disorders, have been shown to lead to many of the changes in cervical cells that may eventually lead to cancer.
Genetic material that comes from certain forms of HPV has been found in cervical tissues that show cancerous or precancerous changes.
In addition, women who have been diagnosed with HPV are more likely to develop a cervical cancer that has genetic material matching the strain of virus that caused the infection.
These findings demonstrate a strong link between the virus and cervical cancer.
Because HPV can be transmitted by sexual contact, early sexual contact and having multiple sexual partners have been identified as strong risk factors for the development of cervical lesions that may progress to cancer.
Cigarette smoking is another risk factor for the development of cervical cancer. The chemicals in cigarette smoke interact with the cells of the cervix, causing precancerous changes that may over time progress to cancer.
Oral contraceptives ("the pill") may increase the risk for cervical cancer, especially in women who use oral contraceptives for longer than 5 years
fr: many sources
Cervical Cancer de Symptoms
As in many cancers, you may have no signs or symptoms of cervical cancer until it has progressed to a dangerous stage.
Cervical cancer does not usually cause pain, although it may in very advanced stages.
The most common symptom is abnormal vaginal bleeding. This is any bleeding from the vagina other than during menstruation.
Abnormal vaginal discharge also may occur with cervical cancer.
Cervical cancer does not usually cause pain, although it may in very advanced stages.
The most common symptom is abnormal vaginal bleeding. This is any bleeding from the vagina other than during menstruation.
Abnormal vaginal discharge also may occur with cervical cancer.
breast canCer _ Medical Treatment
Many women have treatment in addition to surgery, which may include radiation therapy, chemotherapy, or hormonal therapy. The decision about which additional treatments are needed is based upon the stage and type of cancer, the presence of hormonal and/or HER-2/neu receptors, and patient health and preferences.
Radiation therapy is used to kill tumor cells if there are any left after surgery.
Radiation is a local treatment and therefore works only on tumor cells that are directly in its beam.
Radiation is used most often in people who have undergone conservative surgery such as lumpectomy. Conservative surgery is designed to leave as much of the breast tissue in place as possible.
Radiation therapy is usually given five days a week over five to six weeks. Each treatment takes only a few minutes.
Radiation therapy is painless and has relatively few side effects. However, it can irritate the skin or cause a burn similar to a bad sunburn in the area.
Chemotherapy consists of the administration of medications that kill cancer cells or stop them from growing. In breast cancer, three different chemotherapy strategies may be used:
1. Adjuvant chemotherapy is given to people who have had curative treatment for their breast cancer, such as surgery and radiation. It is given to reduce the possibility that the cancer will return.2. Presurgical chemotherapy is given to shrink a large tumor and/or to kill stray cancer cells. This increases the chances that surgery will get rid of the cancer completely.3. Therapeutic chemotherapy is routinely administered to women with breast cancer that has spread beyond the confines of the breast or local area.
Most chemotherapy agents are given through an IV line, but some are given as pills.
Chemotherapy is usually given in "cycles." Each cycle includes a period of intensive treatment lasting a few days or weeks followed by a week or two of recovery. Most people with breast cancer receive at least two, more often four, cycles of chemotherapy to begin with. Tests are then repeated to see what effect the therapy has had on the cancer.
Chemotherapy differs from radiation in that it treats the entire body and thus may target stray tumor cells that may have migrated from the breast area.
The side effects of chemotherapy are well known. Side effects depend on which drugs are used. Many of these drugs have side effects that include loss of hair, nausea and vomiting, loss of appetite, fatigue, and low blood cell counts. Low blood counts may cause patients to be more susceptible to infections, to feel sick and tired, or to bleed more easily than usual. Medications are available to treat or prevent many of these side effects.
Hormonal therapy may be given because breast cancers (especially those that have ample estrogen or progesterone receptors) are frequently sensitive to changes in hormones. Hormonal therapy may be given to prevent recurrence of a tumor or for treatment of existing disease.
In some cases, it is beneficial to suppress a woman's natural hormones with drugs; in others, it is beneficial to add hormones.
In premenopausal women, ovarian ablation (removal of the hormonal effects of the ovary) may be useful. This can be accomplished with medications that block the ovaries' ability to produce estrogens or by surgically removing the ovaries, or less commonly with radiation.
Until recently, tamoxifen (Nolvadex), an antiestrogen (a drug that blocks the effect of estrogen), has been the most commonly prescribed hormone treatment. It is used both for breast cancer prevention and for treatment.
Fulvestrant (Faslodex) is another drug that acts via the estrogen receptor, but instead of blocking it, this drug eliminates it. It can be effective if the breast cancer is no longer responding to tamoxifen. Fulvestrant is only given to women who are already in menopause and is approved for use in women with advanced breast cancer.
Toremifene (Fareston) is another anti-estrogen drug closely related to tamoxifen.
Aromatase inhibitors, which block the effect of a key hormone affecting the tumor, may be more effective than tamoxifen in the adjuvant setting. The drugs anastrozole (Arimidex), exemestane (Aromasin), and letrozole (Femera) have a different set of side effects and risks than tamoxifen.
Aromatase inhibitors are rapidly moving into first line hormonal therapy regimens. In addition, they are frequently used after two or more years of tamoxifen therapy.
Megace (megestrol acetate) is a drug similar to progesterone which may also be used as hormonal therapy.
Monoclonal antibodies are antibodies against proteins in or around a cancer cell. Antibodies recognize an "invader"—in this case, a cancer cell—and attack it.
Trastuzumab (Herceptin) is an antibody against the HER-2 protein, a protein responsible for cancer cell growth in many women with breast cancer (about 15-25% of breast cancers). Adding treatment with trastuzumab to chemotherapy given after surgery has been shown to lower the recurrence rate and death rate in women with HER2/neu-positive early breast cancers. Using trastuzumab along with chemotherapy has become standard adjuvant treatment for these women.
Lapatinib (Tykerb) is another drug that targets the HER2/neu protein and may be given combined with chemotherapy. It is used in women with HER2-positive breast cancer that is no longer helped by chemotherapy and trastuzumab.
Another monoclonal antibody, Bevacixumab (Avastin) has been shown to have activity in the treatment of breast cancer and is used in combination with chemotherapy. This drug targets the ability of cancers cells to form new blood vessels.
Surgery
Surgery is generally the first step after the diagnosis of breast cancer. The type of surgery is dependent upon the size and type of tumor and the patient's health and preferences.
Lumpectomy involves removal of the cancerous tissue and a surrounding area of normal tissue. This is not considered curative and should almost always be done in association with other therapy such as radiation therapy with or without chemotherapy or hormonal therapy.
At the time of lumpectomy, the axillary lymph nodes (the glands in the armpit) need to be evaluated for the spread of cancer. This can be done by either removing the lymph nodes or by sentinel node biopsy (biopsy of the closest lymph node to the tumor).
If a sentinel node biopsy is done at the time of lumpectomy, it may allow the surgeon to remove only some of the lymph nodes. In this procedure, a dye is injected into the area of the tumor. The path of the substance is then followed as it travels to the lymph nodes. The first node reached is the sentinel node. This node is considered most important to biopsy when evaluating the spread of the tumor.
If the sentinel node biopsy is positive, the surgeon will usually remove of all of the lymph nodes found in the axilla (armpit).
Simple mastectomy removes the entire breast but no other structures. If the cancer is invasive, this surgery alone will not cure it. It is a common treatment for DCIS, a noninvasive type of breast cancer.
Modified radical mastectomy removes the breast and the axillary (underarm) lymph nodes but does not remove the underlying muscle of the chest wall. Although additional chemotherapy or hormonal therapy is almost always offered, surgery alone is considered adequate to control the disease if it has not metastasized.
Radical mastectomy involves removal of the breast and the underlying chest wall muscles, as well as the underarm contents. This surgery is no longer done because current therapies are less disfiguring and have fewer complications.
Fr: many resources
Radiation therapy is used to kill tumor cells if there are any left after surgery.
Radiation is a local treatment and therefore works only on tumor cells that are directly in its beam.
Radiation is used most often in people who have undergone conservative surgery such as lumpectomy. Conservative surgery is designed to leave as much of the breast tissue in place as possible.
Radiation therapy is usually given five days a week over five to six weeks. Each treatment takes only a few minutes.
Radiation therapy is painless and has relatively few side effects. However, it can irritate the skin or cause a burn similar to a bad sunburn in the area.
Chemotherapy consists of the administration of medications that kill cancer cells or stop them from growing. In breast cancer, three different chemotherapy strategies may be used:
1. Adjuvant chemotherapy is given to people who have had curative treatment for their breast cancer, such as surgery and radiation. It is given to reduce the possibility that the cancer will return.2. Presurgical chemotherapy is given to shrink a large tumor and/or to kill stray cancer cells. This increases the chances that surgery will get rid of the cancer completely.3. Therapeutic chemotherapy is routinely administered to women with breast cancer that has spread beyond the confines of the breast or local area.
Most chemotherapy agents are given through an IV line, but some are given as pills.
Chemotherapy is usually given in "cycles." Each cycle includes a period of intensive treatment lasting a few days or weeks followed by a week or two of recovery. Most people with breast cancer receive at least two, more often four, cycles of chemotherapy to begin with. Tests are then repeated to see what effect the therapy has had on the cancer.
Chemotherapy differs from radiation in that it treats the entire body and thus may target stray tumor cells that may have migrated from the breast area.
The side effects of chemotherapy are well known. Side effects depend on which drugs are used. Many of these drugs have side effects that include loss of hair, nausea and vomiting, loss of appetite, fatigue, and low blood cell counts. Low blood counts may cause patients to be more susceptible to infections, to feel sick and tired, or to bleed more easily than usual. Medications are available to treat or prevent many of these side effects.
Hormonal therapy may be given because breast cancers (especially those that have ample estrogen or progesterone receptors) are frequently sensitive to changes in hormones. Hormonal therapy may be given to prevent recurrence of a tumor or for treatment of existing disease.
In some cases, it is beneficial to suppress a woman's natural hormones with drugs; in others, it is beneficial to add hormones.
In premenopausal women, ovarian ablation (removal of the hormonal effects of the ovary) may be useful. This can be accomplished with medications that block the ovaries' ability to produce estrogens or by surgically removing the ovaries, or less commonly with radiation.
Until recently, tamoxifen (Nolvadex), an antiestrogen (a drug that blocks the effect of estrogen), has been the most commonly prescribed hormone treatment. It is used both for breast cancer prevention and for treatment.
Fulvestrant (Faslodex) is another drug that acts via the estrogen receptor, but instead of blocking it, this drug eliminates it. It can be effective if the breast cancer is no longer responding to tamoxifen. Fulvestrant is only given to women who are already in menopause and is approved for use in women with advanced breast cancer.
Toremifene (Fareston) is another anti-estrogen drug closely related to tamoxifen.
Aromatase inhibitors, which block the effect of a key hormone affecting the tumor, may be more effective than tamoxifen in the adjuvant setting. The drugs anastrozole (Arimidex), exemestane (Aromasin), and letrozole (Femera) have a different set of side effects and risks than tamoxifen.
Aromatase inhibitors are rapidly moving into first line hormonal therapy regimens. In addition, they are frequently used after two or more years of tamoxifen therapy.
Megace (megestrol acetate) is a drug similar to progesterone which may also be used as hormonal therapy.
Monoclonal antibodies are antibodies against proteins in or around a cancer cell. Antibodies recognize an "invader"—in this case, a cancer cell—and attack it.
Trastuzumab (Herceptin) is an antibody against the HER-2 protein, a protein responsible for cancer cell growth in many women with breast cancer (about 15-25% of breast cancers). Adding treatment with trastuzumab to chemotherapy given after surgery has been shown to lower the recurrence rate and death rate in women with HER2/neu-positive early breast cancers. Using trastuzumab along with chemotherapy has become standard adjuvant treatment for these women.
Lapatinib (Tykerb) is another drug that targets the HER2/neu protein and may be given combined with chemotherapy. It is used in women with HER2-positive breast cancer that is no longer helped by chemotherapy and trastuzumab.
Another monoclonal antibody, Bevacixumab (Avastin) has been shown to have activity in the treatment of breast cancer and is used in combination with chemotherapy. This drug targets the ability of cancers cells to form new blood vessels.
Surgery
Surgery is generally the first step after the diagnosis of breast cancer. The type of surgery is dependent upon the size and type of tumor and the patient's health and preferences.
Lumpectomy involves removal of the cancerous tissue and a surrounding area of normal tissue. This is not considered curative and should almost always be done in association with other therapy such as radiation therapy with or without chemotherapy or hormonal therapy.
At the time of lumpectomy, the axillary lymph nodes (the glands in the armpit) need to be evaluated for the spread of cancer. This can be done by either removing the lymph nodes or by sentinel node biopsy (biopsy of the closest lymph node to the tumor).
If a sentinel node biopsy is done at the time of lumpectomy, it may allow the surgeon to remove only some of the lymph nodes. In this procedure, a dye is injected into the area of the tumor. The path of the substance is then followed as it travels to the lymph nodes. The first node reached is the sentinel node. This node is considered most important to biopsy when evaluating the spread of the tumor.
If the sentinel node biopsy is positive, the surgeon will usually remove of all of the lymph nodes found in the axilla (armpit).
Simple mastectomy removes the entire breast but no other structures. If the cancer is invasive, this surgery alone will not cure it. It is a common treatment for DCIS, a noninvasive type of breast cancer.
Modified radical mastectomy removes the breast and the axillary (underarm) lymph nodes but does not remove the underlying muscle of the chest wall. Although additional chemotherapy or hormonal therapy is almost always offered, surgery alone is considered adequate to control the disease if it has not metastasized.
Radical mastectomy involves removal of the breast and the underlying chest wall muscles, as well as the underarm contents. This surgery is no longer done because current therapies are less disfiguring and have fewer complications.
Fr: many resources
Phytoestrogen
Soybeans contain isoflavones called genistein and daidzein, which are one source of phytoestrogens in the human diet. Since most naturally occurring estrogenic substances show only weak activity, it is doubtful that normal consumption of foods that contain these phytoestrogens would provide sufficient amounts to elicit a physiological response in humans.[citation needed]
Plant lignans associated with high fiber foods such as cereal brans and beans are the principal precursor to mammalian lignans which have an ability to bind to human estrogen sites. Soybeans are a significant source of mammalian lignan precursor secoisolariciresinol containing 13–273 µg/100 g dry weight.[39] Another phytoestrogen in the human diet with estrogen activity is coumestans, which are found in beans, split-peas, with the best sources being alfalfa, clover, and soybean sprouts. Coumestrol, an isoflavone coumarin derivative is the only coumestan in foods.
Soybeans and processed soy foods do not contain the highest "total phytoestrogen" content of foods. A study in which data were presented on an as is (wet) basis per 100 g and per serving found that food groups with decreasing levels of total phytoestrogens per 100 g are nuts and oilseeds, soy products, cereals and breads, legumes, meat products, various processed foods that may contain soy, vegetables, and fruits.
In men
Because of the phytoestrogen content, some studies indicate that there is an inverse correlation between soybean ingestion and testosterone in men. For this reason, they may be protected against the development of prostate cancer.
In women
A 2001 lierature review suggested that women with current or past breast cancer should be aware of the risks of potential tumor growth when taking soy products, based on the effect of phytoestrogens on breast cancer cell growth in animals.
A 2006 commentary reviewed the relationship with soy and breast cancer. They stated that soy may prevent breast cancer, but cautioned that the impact of isoflavones on breast tissue needs to be evaluated at the cellular level in women at high risk for breast cancer.
In infant formula
There are some studies that state that phytoestrogen in soy can lead to alterations in the proliferation and migration of intestinal cells. The effects of these alterations are unknown.[47] However, some studies conclude there are no adverse effects in human growth, development, or reproduction as a result of the consumption of soy-based infant formula.[48] Other reviews agree, but state that more research is needed to answer the question of what effect phytoestrogens have on infants. Soy formula has also been linked to autoimmune disorders of the thyroid gland.
About 8% of children in the
As a carcinogen
Fr: many resources..
AntiOksidan
Kunci Sehat Penangkal Penuaan Dini
Siapapun orangnya, kita pasti ingin panjang umur dengan kesehatan yang selalu baik. Berbagai upaya utnuk mewujudkan hal itu perlu dilakukan sejak usia muda. Sayangnya, kebanyakan dari kita baru menyadari bahwa mereka sedang memasuki proses penuaan (aging) ketika mulai mengalami perubahan-perubahan, abik fisik maupun psikis. Menjadi tua adalah takdir, hukum alam yang tak dapat kita hindari. Namun, kini para ahli dengan segala penemuannya berpendapat bahwa proses takdir itu dapat diperlambat. Tersebutlah zat yang bernama ANTIOKSIDAN. Lalu, apa dan bagaimana peran antioksidan ini dalam menghambat penuaan.
Antioksidan Zat Penghambat Proses Penuaan
Antioksidan merupakan zat yang anti terhadap zat lain yang bekerja sebagai oksidan atau lebih popular disebut radikal bebas. Radikal bebas adalah sejenis oksigen yang susunan atomnya tidak sempurna. Zat ini merupakan zat berbahaya yang sangat reaktif dan bersifat merusak jaringan organ-organ tubuh hingga menimbulkan berbagai penyakit di usia tua. Bagaimana bisa muncul radikal bebas ini? Radikal bebas muncul sebagai dampak dari adanya kehidupan itu sendiri. Setiap makhluk hidup perlu energy untuk bertahan hidup. Makhluk hidup termasuk manusia, akan selalu memproduksi radikal bebas sebagai produk samping dari proses pembentukan energy. Energy itu diperoleh dari hasil metabolisme dengan mengoksidasi (membakar) zat-zat makanan, seperti karbohidrat, lemak dan protein. Dalam proses oksidasi itulah radikal bebas, turut diproduksi.
Selain lahir dari proses metabolisme, radikal bebas juga muncul pada setiap kejadian pembakaran, misalnya merokok, memasak, juga aktifitas pembakaran bahan bakar bermotor dan mesin, memasak, dan lain sebagainya. Ketika sinar ultra violet menerpa suatu benda terus meneru, electron atom benda tersebut akan meloncat dari oritnya, dan terciptalah radikal bebas.
Singkatnya, radikal bebas akan selalu bertebaran dimana-mana. Api adalah radikal bebas yang dapat dilihat dengan mata. Layaknya radikal bebas, sifat api pun sangat reaktif dan sulit dikendalikan jika merajalela.
Supaya radikal bebas tidak merajalela, tubuh dengan sendirinya akan spontan memproduksi zat antioksidannya. Antioksidan yang diproduksi dari dalam tubuh (endogen) berupa tiga enzim yaitu, superoksida dismutase (SOD), glutation peroksidase (GSH Px), katalase, serta non enzim, yaitu senyawa protein kecil glutation.
Ketiga enzim dan senyawa glutation itu bekerja menetralkan radikal bebas. Pekerjaannya itu dibantu oleh asupan antioksidan dari luar (endogen) yang berasal dari bahan makanan. Misalnya vitamin E, C, betakaroten dan senyawa flavanoidyang diperoleh dari tumbuhan.
Hasil penelitian ilmiah menunjukkan bahwa buah-buahan, sayuran dan biji-bijian adalah sumber antioksidan yang baik dan bias meredam reaksi berantai radikal bebas dalam tubuh, yang pada akhirnya dapat menekan proses penuaan dini. Tomat mengandung likopene, yakni antioksidan yang ampuh menghentikan radikal bebas sehingga tak berkeliaran mencari asam lemak tak jenuh dalam sel. Hal yang sama dilakukan lutein dan zeasantin yang terdapat pada bayam, diketahui amat aktif mencegah reaksi oksidasi lipid pada membran sel lensa (mata), sehingga kita dapat terhindar dari katarak. Sedangkan antioksidan vitamin seperti vitamin C, E dan betakarotenoid akan menstabilkan membrane sel lensa dan mempertahankan konsentrasi glutation tereduksi dalam lensa.
Data Ilmiah menyebutkan, individu yang rajin mengkonsumsi buah dan sayur memiliki peluang untuk awet muda dan terhindar dari penyakit yang terkait dengan penuaan seperti kanker dan pernafasan.
Langkah sehat lainya adalah mengurangi asupan jumlah kalori yang berasal dari karbohidrat dan lemak. Kalori dapat mempercepat penuaan dini karena untuk mengubahnya menjadi energy diperlukan lebih banyak oksigen. Namun, di lain pihak oksigen memicu banyak radikal bebas yang bersumber dari senyawa reaktif oksigen, yang kemudian menyerang sel-sel dan akhirnya mempercepat proses penuaan. Oleh sebab itu, ayo kita perbanyak asupan antioksidan.
Siapapun orangnya, kita pasti ingin panjang umur dengan kesehatan yang selalu baik. Berbagai upaya utnuk mewujudkan hal itu perlu dilakukan sejak usia muda. Sayangnya, kebanyakan dari kita baru menyadari bahwa mereka sedang memasuki proses penuaan (aging) ketika mulai mengalami perubahan-perubahan, abik fisik maupun psikis. Menjadi tua adalah takdir, hukum alam yang tak dapat kita hindari. Namun, kini para ahli dengan segala penemuannya berpendapat bahwa proses takdir itu dapat diperlambat. Tersebutlah zat yang bernama ANTIOKSIDAN. Lalu, apa dan bagaimana peran antioksidan ini dalam menghambat penuaan.
Antioksidan Zat Penghambat Proses Penuaan
Antioksidan merupakan zat yang anti terhadap zat lain yang bekerja sebagai oksidan atau lebih popular disebut radikal bebas. Radikal bebas adalah sejenis oksigen yang susunan atomnya tidak sempurna. Zat ini merupakan zat berbahaya yang sangat reaktif dan bersifat merusak jaringan organ-organ tubuh hingga menimbulkan berbagai penyakit di usia tua. Bagaimana bisa muncul radikal bebas ini? Radikal bebas muncul sebagai dampak dari adanya kehidupan itu sendiri. Setiap makhluk hidup perlu energy untuk bertahan hidup. Makhluk hidup termasuk manusia, akan selalu memproduksi radikal bebas sebagai produk samping dari proses pembentukan energy. Energy itu diperoleh dari hasil metabolisme dengan mengoksidasi (membakar) zat-zat makanan, seperti karbohidrat, lemak dan protein. Dalam proses oksidasi itulah radikal bebas, turut diproduksi.
Selain lahir dari proses metabolisme, radikal bebas juga muncul pada setiap kejadian pembakaran, misalnya merokok, memasak, juga aktifitas pembakaran bahan bakar bermotor dan mesin, memasak, dan lain sebagainya. Ketika sinar ultra violet menerpa suatu benda terus meneru, electron atom benda tersebut akan meloncat dari oritnya, dan terciptalah radikal bebas.
Singkatnya, radikal bebas akan selalu bertebaran dimana-mana. Api adalah radikal bebas yang dapat dilihat dengan mata. Layaknya radikal bebas, sifat api pun sangat reaktif dan sulit dikendalikan jika merajalela.
Supaya radikal bebas tidak merajalela, tubuh dengan sendirinya akan spontan memproduksi zat antioksidannya. Antioksidan yang diproduksi dari dalam tubuh (endogen) berupa tiga enzim yaitu, superoksida dismutase (SOD), glutation peroksidase (GSH Px), katalase, serta non enzim, yaitu senyawa protein kecil glutation.
Ketiga enzim dan senyawa glutation itu bekerja menetralkan radikal bebas. Pekerjaannya itu dibantu oleh asupan antioksidan dari luar (endogen) yang berasal dari bahan makanan. Misalnya vitamin E, C, betakaroten dan senyawa flavanoidyang diperoleh dari tumbuhan.
Cara Kerja Antioksidan
Antioksidan menghalangi proses oksidasi dengancara menetralisir radikal bebas. Dalam proses itu antioksidan pun teroksidasi. Itulah mengapa kita harus terus menerus “mengisi ulang” antioksidan dalam tubuh kita.
Antioksidan bekerja dalam dua cara:
1. Pemutusan rantai – Saat radikal bebas melepaskan atau mengambil electron, radikal bebas lain akan terbentuk. Lalu molekul ini akan berputar dan melakukan hal yang sama pada molekul yang lain, dan menghasilkan molekul lain, begitu seterusnya. Proses ini terus berlangsung sampai terjadi pemutusan atau radikalbebas itu sudah distabilkan oleh antioksidan “pemutus rantai” seperti betakaroten, vitamin C dan E
2. Pencegahan – dengan cara mengurangi tingkat inisiasi rantai, yaitu dengan memicu inisiasi radikal bebas, antioksidan dapat merintangi pemutusan rantai oksidasi. Mereka juga dapat mencagah oksidasi dengan cara menstabilkan transisi logam berat seperti tembaga dan besi.
Efektifitas kerja antioksidan tergantung dari jumlah, bagaimana dan dimana radikal bebas dihasilkan serta target kerusakannya. Dengan begitu, dalam suatu proses oksidan dapat melindungi kita dari pengaruh radikal bebas, pada sistem lain tidak berefek sama sekali. Bahkan dalam keadaan tertentu antioksidan dapat bertindak meningkatkan proses oksidasi dengan menghasilkan jenis oksigen yang membahayakan.
Sumber AntioksidanAntioksidan menghalangi proses oksidasi dengancara menetralisir radikal bebas. Dalam proses itu antioksidan pun teroksidasi. Itulah mengapa kita harus terus menerus “mengisi ulang” antioksidan dalam tubuh kita.
Antioksidan bekerja dalam dua cara:
1. Pemutusan rantai – Saat radikal bebas melepaskan atau mengambil electron, radikal bebas lain akan terbentuk. Lalu molekul ini akan berputar dan melakukan hal yang sama pada molekul yang lain, dan menghasilkan molekul lain, begitu seterusnya. Proses ini terus berlangsung sampai terjadi pemutusan atau radikalbebas itu sudah distabilkan oleh antioksidan “pemutus rantai” seperti betakaroten, vitamin C dan E
2. Pencegahan – dengan cara mengurangi tingkat inisiasi rantai, yaitu dengan memicu inisiasi radikal bebas, antioksidan dapat merintangi pemutusan rantai oksidasi. Mereka juga dapat mencagah oksidasi dengan cara menstabilkan transisi logam berat seperti tembaga dan besi.
Efektifitas kerja antioksidan tergantung dari jumlah, bagaimana dan dimana radikal bebas dihasilkan serta target kerusakannya. Dengan begitu, dalam suatu proses oksidan dapat melindungi kita dari pengaruh radikal bebas, pada sistem lain tidak berefek sama sekali. Bahkan dalam keadaan tertentu antioksidan dapat bertindak meningkatkan proses oksidasi dengan menghasilkan jenis oksigen yang membahayakan.
Hasil penelitian ilmiah menunjukkan bahwa buah-buahan, sayuran dan biji-bijian adalah sumber antioksidan yang baik dan bias meredam reaksi berantai radikal bebas dalam tubuh, yang pada akhirnya dapat menekan proses penuaan dini. Tomat mengandung likopene, yakni antioksidan yang ampuh menghentikan radikal bebas sehingga tak berkeliaran mencari asam lemak tak jenuh dalam sel. Hal yang sama dilakukan lutein dan zeasantin yang terdapat pada bayam, diketahui amat aktif mencegah reaksi oksidasi lipid pada membran sel lensa (mata), sehingga kita dapat terhindar dari katarak. Sedangkan antioksidan vitamin seperti vitamin C, E dan betakarotenoid akan menstabilkan membrane sel lensa dan mempertahankan konsentrasi glutation tereduksi dalam lensa.
Data Ilmiah menyebutkan, individu yang rajin mengkonsumsi buah dan sayur memiliki peluang untuk awet muda dan terhindar dari penyakit yang terkait dengan penuaan seperti kanker dan pernafasan.
Langkah sehat lainya adalah mengurangi asupan jumlah kalori yang berasal dari karbohidrat dan lemak. Kalori dapat mempercepat penuaan dini karena untuk mengubahnya menjadi energy diperlukan lebih banyak oksigen. Namun, di lain pihak oksigen memicu banyak radikal bebas yang bersumber dari senyawa reaktif oksigen, yang kemudian menyerang sel-sel dan akhirnya mempercepat proses penuaan. Oleh sebab itu, ayo kita perbanyak asupan antioksidan.
dari SUPERNOVA de NOVEL
10 Juli 2008 selesai jam 02.00
aku baca kembali buku SUPERNOVA-nya Dewi Lestari, hanya dalam 5 jam saja. Lalu aku ingat kamu.
“di jaring laba-laba supertipis dan besar ini kuyakinkan
Kamu mendengar gaung namamu kupanggil.
Honey… sedang apa kamu? Tertidur?
Ilusi dan kretifitas melayut dalam otakku
Gambaran keakuan merebak di situs kemanusiaan
Dimana aku berdiri? Siapa aku?
Apa mauku bila bertemu denganmu?
Tidak ada yang kebetulan di mata Tuhan
Semua sudah ada
Semua nyata
Begitu juga dengan rasa ini, meski penyangkalan harus dikatakan
Yang ada hanyalah ada
Tanpa tedensi menghakimi
Tuhan Maha Sempurna, bahkan ketika kita punya segala
Nama baik, harta, ibadah
Runtutan peristiwa yang membunuhku
Dan membiarkan diri terlena dalam kematian
Yah…, aku menikmatinya
Nikmatnya hidup dalam mati
Ketika aku mati di dalam kehidupan
Apa yang tertuang di sini semata ingatku padanya. Tuhanku
Karena Kau yang buat hidup, mati, atau apapun,
Menjadi satu makna,
Pengabdian dalam mengagumiMu
Untuk kagumi diriMu sendiri..Untuk hati yang tidak pernah mati
aku baca kembali buku SUPERNOVA-nya Dewi Lestari, hanya dalam 5 jam saja. Lalu aku ingat kamu.
“di jaring laba-laba supertipis dan besar ini kuyakinkan
Kamu mendengar gaung namamu kupanggil.
Honey… sedang apa kamu? Tertidur?
Ilusi dan kretifitas melayut dalam otakku
Gambaran keakuan merebak di situs kemanusiaan
Dimana aku berdiri? Siapa aku?
Apa mauku bila bertemu denganmu?
Tidak ada yang kebetulan di mata Tuhan
Semua sudah ada
Semua nyata
Begitu juga dengan rasa ini, meski penyangkalan harus dikatakan
Yang ada hanyalah ada
Tanpa tedensi menghakimi
Tuhan Maha Sempurna, bahkan ketika kita punya segala
Nama baik, harta, ibadah
Runtutan peristiwa yang membunuhku
Dan membiarkan diri terlena dalam kematian
Yah…, aku menikmatinya
Nikmatnya hidup dalam mati
Ketika aku mati di dalam kehidupan
Apa yang tertuang di sini semata ingatku padanya. Tuhanku
Karena Kau yang buat hidup, mati, atau apapun,
Menjadi satu makna,
Pengabdian dalam mengagumiMu
Untuk kagumi diriMu sendiri..Untuk hati yang tidak pernah mati
Satu HAri tak Termemoar
Honey..
Bila mentari tercabut tugasnya
Biarkan kasihku menerangi harimu
Meski gulita menyelimutimuTetap cahaya doaku mengiringimu
Honey…
Bersama putaran bumi kunanti kita bersua
Meski itu hanya lemparan senyuman
Ataupun lambaian tangan
Mungkin akan kucukupkan
Honey..
Ijinkan aku memujamu dalam doaku
Inginkanmu dalam sepiku,
Karena gundah ini hilang oleh
Senyummu.
Bila mentari tercabut tugasnya
Biarkan kasihku menerangi harimu
Meski gulita menyelimutimuTetap cahaya doaku mengiringimu
Honey…
Bersama putaran bumi kunanti kita bersua
Meski itu hanya lemparan senyuman
Ataupun lambaian tangan
Terbitkan Entri
Mungkin akan kucukupkan
Honey..
Ijinkan aku memujamu dalam doaku
Inginkanmu dalam sepiku,
Karena gundah ini hilang oleh
Senyummu.
Ketika Cinta itu TerLalu BESAR
"Allah tidak akan membebani hambanya melebihi kemampuannya" Ketika apa yang kita kategorikan sebagai musibah, maka kalimat Allah yang inilah yang harus diingat. Musibah atau apapun itu yang bikin hati dan jiwa gelisah, tidak akan membuat kita terpuruk lebih dalam bila kita kembali pada tuhan. karena semua datang dari rasa cinta tuhan kepada kita. Mungkin selama ini kita sedikit terlupa dengan Dia, terlena akan fatamorgana dunia, nikmat yang semu atau kebahagiaan yang membutakan mata hati. Kita jarang sekali menghitung kecintaan Tuhan pada kita, yang sering kita lakukan adalah menghitung berapa banyak do'a kita yang belum terkabul. tanya hati, sedekat apakah kita dengan Dia? Bayangkan, kalau anda adalah seorang karyawan di satu kantor, bekerja dengan sebaik mungkin, untuk penilaian tahunan yang menentukan kenaikan gaji, itu saja anda perbuat dengan sepenuh hati, bahkan ada sebagian yang "bermain dari samping" untuk mendapatkan simpati atasan. Bagaimana dengan tuhanMU?? Sudah sedekat apa kita dengan Nya? Apa pantas minta banyak bila mengingatnya juga jarang?? jadi tak selamanya musibah itu sekedar musibah. Bisa jadi itu ilmu. Geser sedikit pandangan, coba pandang dari sisi hati nurani. Akan banyak sekali rezeki yang tak terduga menghampiri hati. Insya Allah.
Belum Ada JuDul
Ku tak bisa menemukan judul yang tepat untuk postingan ini. Yang kurasakan hanya kekosongan yang damai. Mungkin terdengar aneh, apalagi rasanya.
Tolong Tuhan, beri hatiku kelapangan yang Kau ridhoi, seluas apa yang kubutuhkan untuk menampung KasihMu, Yang Maha Besar,.
Sering kutitipkan sejumput salam untuknya (semoga tersampaikan, amin) di samping sisi cinta di hati yang kuberikan untuk dia. Dia yang selama hampir 2 dekade menemani kehidupanku.
Hanya saja rasa ini terlalu besar untukku, hingga kutak bisa membuat batas yang jelas untuknya dan dia.
Tuhanku yang Maha Penyayang, berilah aku petunjuk, jangan biarkan aku terjebak lebih jauh dalam cinta ini. Kau MAha TAu
Tolong Tuhan, beri hatiku kelapangan yang Kau ridhoi, seluas apa yang kubutuhkan untuk menampung KasihMu, Yang Maha Besar,.
Sering kutitipkan sejumput salam untuknya (semoga tersampaikan, amin) di samping sisi cinta di hati yang kuberikan untuk dia. Dia yang selama hampir 2 dekade menemani kehidupanku.
Hanya saja rasa ini terlalu besar untukku, hingga kutak bisa membuat batas yang jelas untuknya dan dia.
Tuhanku yang Maha Penyayang, berilah aku petunjuk, jangan biarkan aku terjebak lebih jauh dalam cinta ini. Kau MAha TAu
22 March 2009
Rahasia Indah
"tak terbayangkan berjumpa dengan dirimu,
menjadi awal kisah kita berdua,
terlanjur jauh sudah kujatuh hati padamu,
tanpa kufikir lagi ternyata ku salah......
dia yang pantas mendapat cinta darimu,
karena dia yang pertama mencintamu,
kini berakhir sudah kepada keputusanku,
walaupun itu pedih kurela kau pergi.....
Mengapa tak katakan kau tlah berdua,
Mengapa berdusta tuk raih cintaku,
mestinya kau jujur padaku, tulus padaku,
mungkin ku tak membalas,
kutak mau berbagi cinta dengannya,
karna kutak ingin ada yang terluka,
biarlah yang lalu menjadi sebuah rahasia
indah kita berdua"
(song by Ale)
menjadi awal kisah kita berdua,
terlanjur jauh sudah kujatuh hati padamu,
tanpa kufikir lagi ternyata ku salah......
dia yang pantas mendapat cinta darimu,
karena dia yang pertama mencintamu,
kini berakhir sudah kepada keputusanku,
walaupun itu pedih kurela kau pergi.....
Mengapa tak katakan kau tlah berdua,
Mengapa berdusta tuk raih cintaku,
mestinya kau jujur padaku, tulus padaku,
mungkin ku tak membalas,
kutak mau berbagi cinta dengannya,
karna kutak ingin ada yang terluka,
biarlah yang lalu menjadi sebuah rahasia
indah kita berdua"
(song by Ale)
sahabat
internet memang membnu mencari "kepompong2ku" yang hilang. tapi kayaknya... kawan2 SD dan smp ku saja yang gemar maen inet. udah hampir 15 taon menjelajah dunia maya.. sampe sekrang belom ketemu tuh anak2 analis depkes taon 92... kemana kelen woiii.....
hidup dengan sahabat
Kemaren beli novel "An Affair to forget (cinta saja tidak cukup)". mengingatkan ku pada beberapa sahabat dekaat banget waktu sekolah dulu, sahabat kekasihku, atau aku hanya ingin mencari pembuktian bahwa aku tidak termasuk dalam salah satu tokoh di novel itu.
Cinta memang tak bisa dimengerti karena letaknya memang bukan di kepala. Seperti kita tau, hati itu wadah untuk rasa, dan rasa akan selalu dinamis.
Kesetiaan bukan jaminan untuk bahagia, karena bahagia itu milik hati dan diciptakan.
Mencoba setia dan terus berusaha untuk setia pada cinta, cuma itu yang bisa kulakukan saat ini.
Cinta memang tak bisa dimengerti karena letaknya memang bukan di kepala. Seperti kita tau, hati itu wadah untuk rasa, dan rasa akan selalu dinamis.
Kesetiaan bukan jaminan untuk bahagia, karena bahagia itu milik hati dan diciptakan.
Mencoba setia dan terus berusaha untuk setia pada cinta, cuma itu yang bisa kulakukan saat ini.
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