"Hemicrania continua": another headache absolutely responsive to indomethacin

Two cases suffering from a headache apparently at variance with well recognized headaches are described. It is characterized by a steady, non-paroxysmal, probably severe to moderately severe hemicrania localized anteriorly or anteroposteriorly and is not associated with nausea. Indomethacin exerts an absolute, persistent and clearly dose-dependent effect on this headache, which differs from unilateral headache syndromes such as cluster headache and cervicogenic headache in its temporal pattern and indomethacin response. It differs from chronic paroxysmal hemicrania in its temporal pattern and in the lack of accompanying symptoms.     

Invasion of erythrocytes by Plasmodium falciparum malaria parasites: evidence for receptor heterogeneity and two receptors

Plasmodium falciparum malaria parasites with different capabilities of invading sialic acid-deficient erythrocytes were identified. Thai-2 parasites cultured in Tn erythrocytes invaded neuraminidase-treated and Tn erythrocytes twice as efficiently as Thai-2 parasites cultured in normal erythrocytes and seven to ten times more efficiently than a cloned line of Camp parasites cultured in normal erythrocytes. All three parasite lines required sialic acid for optimal invasion, but Thai-2 parasites cultured in Tn erythrocytes invaded neuraminidase- treated erythrocytes with 45% efficiency whereas Camp parasites invaded neuraminidase-treated erythrocytes with less than 10% efficiency. P falciparum malaria parasites probably possess two receptors: one that binds to a sialic acid-dependent ligand and another that binds to a sialic acid-independent ligand. Parasites may differ in the quantity or affinity of their receptors for the sialic acid-independent ligand.     

Expression of bcl-xL can confer a multidrug resistance phenotype

It has been suggested that genes that regulate apoptotic cell death may play an important role in determining the sensitivity of tumor cells to chemotherapy. We have recently cloned a member of the bcl-2 family, bcl- x. To test whether bcl-XL expression affects the sensitivity of tumor cells to chemotherapy, we have created stable cell lines overexpressing bcl-XL and have tested these cells for resistance to cell death induced by metabolic inhibitors and chemotherapeutic agents. Bcl-XL expression dramatically reduces the cytotoxicity of bleomycin, cisplatin, etoposide, vincristine, hygromycin B, and mycophenolic acid for up to 4 days in culture. Bcl-XL does not prevent cells from undergoing cell cycle arrest in response to these drugs, but rather prevents treated cells from undergoing apoptosis. Cell-cycle analysis on cells treated with the chemotherapeutic agents bleomycin, cisplatin, etoposide, and vincristine, show that the drugs cause growth arrest in different positions within the cell cycle. Bcl-XL expressing cells treated with chemotherapeutic drugs retain their proliferative ability after the drugs are removed. Interestingly, vincristine-treated cells expressing bcl-XL become polyploid after drug removal. These data show that bcl-XL protects cells from a wide variety of apoptotic stimuli, acts in multiple positions within the cell cycle, and confers a multidrug resistance phenotype. The ability of bcl-XL to prevent apoptotic cell death in response to chemotherapy-induced DNA damage and cell-cycle arrest may contribute to the accumulation of chromosomal aberrations within tumors. The expression of bcl-XL in tumor cells is likely to be an important indicator of chemotherapeutic efficacy.     

The impact of brain temperature and core temperature on intracranial pressure and cerebral perfusion pressure.

Hyperthermia has been demonstrated to increase neuronal injury when present during or after an acute brain injury. The assumption that core temperature equals brain temperature exists. If the temperature of an injured brain is higher than core temperature, episodes of neural hyperthermia may go undetected. The objectives of this study were to (1) determine if differences exist between brain temperature and core temperature in subjects with acute neurological injuries in both normothermic and febrile states and (2) investigate the impact of brain and core temperatures on intracranial pressure (ICP) and cerebral perfusion pressure (CPP). The study was conducted through a retrospective chart audit of patients age 18 years or older admitted to a level I trauma center with a diagnosis of brain injury whose condition warranted placement of a pulmonary artery catheter (which measured core temperature) and an intraventricular catheter (which measured brain temperature). Thirty-one charts contained complete data; nine charts provided partial data. Mean brain temperature (100.8 degrees F, SD = 0.69) was found to be significantly higher than mean core temperature (100.2 degrees F, SD = 0.74; p = .00). Brain temperature means were hyperthermic (> or = 100.9 degrees F), while matching core temperatures were normothermic in almost one-third of the subjects. There was no significant difference found between hyperthermic ICP or CPP and normothermic ICP or CPP determined by brain or core temperature. No significant correlation was found between temperature and intracranial dynamics. Future research is needed with prospectively collected data of adequate sample size to continue to investigate the impact of core and brain temperature on the intracranial dynamics of ICP and CPP.     

胆碱能M受体拮抗剂：2α－（2＇，2＇－二取代基－2＇－羟基乙氧基）托品烷光学异构体合成

胆碱能Ｍ受体拮抗剂：２α－（２＇，２＇－二取代基－２＇－羟基乙氧基）托品烷光学异构体合成王林，恽榴红，张其楷（军事医学科学院毒物药物研究所，北京１００８５０）目前临床所用托品类抗胆碱药一般为３位取代托品酯类衍生物，这类药物作用较广泛，但选择性不高。Ａ...