No abstract

No abstract

Intrathecal (IT) chemotherapy is an important component of the prophylaxis or treatment of hematologic malignancies in the central nervous system (CNS), especially in patients with acute lymphoblastic leukemia and aggressive lymphomas. Different regimens of IT chemotherapies have been formulated, often in conjunction with systemic high-dose chemotherapy leading to penetration of the drugs into the cerebrospinal fluid (CSF). The three commonest IT drugs are methotrexate, cytosine arabinoside (Ara-C), and corticosteroids. The CSF half-lives of methotrexate and Ara-C are much prolonged, a factor to be considered if these drugs are also administered systemically in high doses. Neurotoxicities attributed to IT chemotherapy have been reported, including spinal cord lesions, seizures, and encephalopathy. Spinal cord lesions, manifesting as tetraplegia, paraplegia, and cauda equina syndrome, are the commonest neurotoxicity. It is mostly related to combined IT methotrexate and Ara-C, or Ara-C as the sole IT agent when given at high doses or as a slow-release preparation. Cord lesions rarely recover and patients are left with motor deficits, bowel and urinary disabilities. Seizures and encephalopathy are reported in relatively fewer patients, with variable manifestations and prognosis. Knowledge of the pharmacokinetics, dosing schedules and potential toxicities of IT chemotherapeutic drugs is important in the design of CNS prophylaxis and treatment in hematologic malignancies.

Media self-censorship refers to nonexternally compelled acts committed by media organizations aiming to avoid offending power holders such as the government, advertisers, and major business corporations. While self-censorship constitutes a major threat to press freedom in Hong Kong under China, recent studies have shown that Hong Kong journalists have maintained a strong sense of professionalism. The coexistence of professionalism and self-censorship poses important challenges to news organizations: How is self-censorship effected as professionalism does not favor its practice? How can news organizations minimize the conflicts between self-censorship and professionalism so that news operations will remain stable, smooth, and efficient? Drawing on the literature on newsroom social control, we tackle the above questions by focusing on the internal structure of and the interactive dynamics within newsrooms. Methodologically, this study draws on both representative survey and in-depth interview data. It is found that self-censorship is effected through selective positioning and assignment, observational learning of tacit rules, the giving of ambiguous orders, and the use of professional or technical reasons to justify questionable news decisions. Meanwhile, some journalists also developed their own operational tactics to resist what they perceived as self-censorship attempts. The theoretical implications of the findings are discussed.