And scientists say they've achieved a breakthrough in the treatment of multiple sclerosis after a medical trial involving stem cell transplants.

进行干细胞移植的医学试验后，科学家称其在多发性硬化治疗方面实现了突破。

This also weakens the immune system, making it less likely to attack the transplanted cells.

这也会弱化患者的免疫系统，降低其攻击移植细胞的几率。

Doctors then transplant stem cells from individuals with a genetic mutation which makes them resistant to HIV.

然后，医生从具有基因突变的个体身上移植干细胞，这种基因突变使他们对艾滋病毒具有免疫力。

This is the second patient to show no sign of the HIV virus after a similar stem cell transplant.

这是第二例在类似干细胞移植后不显示HIV病毒迹象的患者。

If you transplant those cells into somebody who already has HIV, you may protect those new cells from from infection.

如果将这些细胞移植到已经患有HIV的人身上，可以保护这些新细胞免受感染。

Instead, they can transplant cells or even entire corneas from other people.

相反，他们可以移植其他人的细胞甚至整个角膜。

However, bone marrow transplants are a complicated process requiring antigen compatibility between the donor and recipient to keep the transplanted cells from from attacking the patient's own cells as foreign bodies.

然而，骨髓移植的过程很复杂，它要求捐献者和患者间的抗原能够匹配，这样才能防治移植的细胞攻击患者自身细胞。

Some T cells (T8 cells) are cytotoxic or killer cells; they act directly on cells bearing antigen (tumor cells and tissue transplanted from an organ donor).

一些T细胞（T 细胞）是细胞毒性或杀伤细胞;它们直接作用于携带抗原的细胞（肿瘤细胞和从器官供体移植的组织）。

His doctor, who was aware of Brown's HIV status, had the foresight to find a special donor for Brown who carried a mutation that would make it impossible for HIV to infect his newly transplanted cells.

他的医生，对布朗的艾滋病病毒感染状况了然于胸，颇有远见地为布朗找到了一位特殊的捐赠者，该捐赠者携带了一种突变，HIV无法感染他新移植的细胞。

Using a camera sensitive to near-infrared light, researchers were able to detect single transplanted tumor cells in the lung of a living mouse, the equivalent of detecting a single firefly in a space the size of a high school gym.

使用对近红外光敏感的相机，研究人员能够在活老鼠的肺部检测到单个移植的肿瘤细胞，相当于在高中体育馆大小的空间中检测到一只萤火虫。