Jichu

Anemia adalah salah satu penyakit yang sering diderita masyarakat, baik anak-anak, remaja usia subur, ibu hamil ataupun orang tua. Penyebabnya sangat beragam, dari yang karena perdarahan, kekurangan zat besi, asam folat, vitamin B 12 , sampai kelainan hemolitik. Anemia dapat diketahui dengan pemeriksaan fisik maupun dengan pemeriksaan laboratorium. Secara fisik penderita tampak pucat, lemah, dan secara laboratorik didapatkan penurunan kadar Hemoglobin (Hb) dalam darah dari harga normal. Anemia adalah suatu kondisi dimana kadar Hb dan/atau hitung eritrosit lebih rendah dari harga normal. Dikatakan sebagai anemia bila Hb < 14 g/dl dan Ht < 41 % pada pria atau Hb < 12 g/dl dan Ht <37 % pada wanita. (Arif Mansjoer,dkk. 2001) Anemia adalah berkurangnya jumlah eritrosit serta jumlah hemoglobin dalam 1mm 3 darah atau berkurangnya volume sel yang dipadatkan (packed red cells volume) dalam 100 ml darah. (Ngastiyah, 1997) Etiologi Penyebab anemia antara lain : 1.   

     Colon cancer is unusual in that the precancerous lesions can be identified early via colonoscopy. Molecular analysis of the various stages of colon cancer is therefore possible. These studies have identified a rough sequence of molecular events that characterize tumor development in colorectal cancer. Because we now know the molecular function many tumor suppressor genes and oncogenes,

     Cells contain many normal genes that are involved in regulating cell proliferation. Some of these genes can be mutated to forms that promote uncontrolled cell proliferation. The normal forms of these genes are called   proto-oncogenes,   while the mutated, cancer-causing forms are called   oncogenes . In contrast to tumor suppressor genes, which put the brakes on cell proliferation, oncogenes actively promote proliferation (analogous to the gas petal of the cell cycle). Mutations that convert proto-oncogenes to oncogenes typically increase the activity of the encoded protein or increase the expression of the normal gene. Such mutations are   dominant   or   gain-of-function mutations . Therefore, only one copy of the gene needs to be mutated in order to promote cancer.Oncogenes were first identified in oncogenic retroviruses that had picked up a cellular oncogene ( c-onc ) and incorporated it into the viral genome to produce a viral oncogene ( v-onc ). J. Michael Bishop and Har

     Tumor suppressor genes can be defined as genes which encode proteins that normally inhibit the formation of tumors. Their normal function is to inhibit cell proliferation, or act as the “brakes” for the cell cycle. Mutations in tumor suppressor genes contribute to the development of cancer by inactivating that inhibitory function. Mutations of this type are termed loss-of-function mutations. As long as the cell contains one functional copy of a given tumor suppressor gene (expressing enough protein to control cell proliferation), that gene can inhibit the formation of tumors. Inactivation of both copies of a tumor suppressor gene is required before their function can be eliminated. Therefore, mutations in tumor suppressor genes are recessive at the level of an individual cell. As we will see, the inactivation of tumor suppressor genes plays a major role in cancer. A. Retinoblastoma      Retinoblastoma (RB) is a rare childhood tumor of the eye (see clinical correlate). Most

When cancer spreads from the part of the body where it started (its primary site) to other parts of the body it’s called metastasis . Metastasis can happen when cells break away from a cancer tumor and travel through the bloodstream or through lymph vessels to other parts of the body. (Lymph vessels are much like blood vessels, except they carry a clear fluid called lymph back toward the heart.) Cancer cells that travel through the blood or lymph vessels can spread to other organs or tissues in distant parts of the body. Many of the cancer cells that break off from the original tumor die without causing any problems. But some settle in a new area. There, they grow and form new tumors. When cancer spreads, we say that it metastasizes. If there’s only a single tumor, it’s called a metastasis or a metastatic tumor . When there are 2 or more metastatic tumors, it’s called metastases . Sometimes metastatic tumors are found on tests done when the primary cancer is first diagnosed. In othe

To identify genes that could discriminate between primary tumors and their synchronous lymph node metastases for the 26 matched pairs of cohort 1, different statistical approaches were undertaken: 1. Unsupervised Hierarchical clustering. A prefiltering of the expression data was performed by taking into account both MAS5 “Absolute Call” flags and average expression measurements within each group. Briefly, from a total number of 44,760 probesets, we selected only the ones called present or marginal (P or M) at least once across all samples, and whose mean raw expression levels were ≥ 200 within at least one class of samples (T, primary tumors, or M, lymph node metastases). The prefiltering method removed those probesets whose expression signal was constantly too close to the background signal throughout the entire set of samples (likely defined as “Absent” by the MAS5 algorithm and consequently not expressed). This procedure allowed the selection of 23,281 probesets. Unsupervise