Influence of protective isolation on outcome of allogeneic bone marrow transplantation for leukemia

Most of the previously published surgical series of suprasellar meningiomas have two disadvantages: (1) patients involved were treated within a relatively long time period, making analysis more difficult, (2) radiographic long term follow-up examinations with either CT- or MRI-scans were not performed. Both disadvantages were overcome in our retrospective clinical study, consisting of 50 consecutive patients with suprasellar meningiomas treated between 1982 and 1991. Radiological, ophthalmological, and neurological investigations were performed preoperatively, postoperatively and at long term follow-up (mean: 5.7 years). A radiologically confirmed radical tumour removal could be achieved in 84% of patients. Both, the peri-operative mortality (2%) and serious operative morbidity (6%) were low. However, 12% of patients developed late onset epilepsy. At long term follow-up, visual function was improved in 67%, unchanged in 9% and worsened in 24%. In more than 50% of patients the vision showed recovery over a longer time period than the first 10 days after operation. Radiographic control examinations revealed tumour recurrences in 2 patients (both asymptomatic) and progress of residual tumour in 5 patients (2 symptomatic, 3 asymptomatic). Since introduction of modern neurosurgery, a clear improvement in the surgical treatment of suprasellar meningiomas can be observed. However, the still long delay in diagnosing these tumours correctly prevents a further improvement of the ophthalmological results at long-term follow-up. Due to a relatively high rate of late onset epilepsy, anticonvulsive prophylaxis for 6 months seems to be justified. Regarding present preoperative diagnostic measures, ia-DSA seems only be indicated in patients with CT/MRI-scans, suspicious for tumourous narrowing or invasion of major cerebral arteries. In addition, we recommend radiographic control examinations at regular time intervals to confirm radical tumour removal and to detect the "ideal" point of time for renewed treatment.     

Computer-assisted design of new drugs based on retrometabolic concepts

Retrometabolic drug design approaches incorporate metabolic and toxicological considerations into the drug design process and represent a novel, systematic methodology for the design of safe compounds. Two major design concepts aimed to increase the therapeutic index (the activity/toxicity ratio) of drugs were developed. Chemical delivery systems (CDS) are primarily used to allow targeting of the active biological molecules to specific target sites or organs based on predictable enzymatic activation. Soft drug approaches are used to design new drugs by building in the molecule, in addition to the activity, the most desired way in which the molecule is to be deactivated and detoxified subsequent to exerting its biological effects. Special computer programs were developed that starting from a lead compound generate complete libraries of possible soft analogs and then help ranking these candidates based on isosteric-isoelectronic comparisons, predicted solubility/partition properties, and estimated metabolic rates. The novel field of large peptide-CDSs imposes special challenges, but a new, remarkably simple model was developed to estimate partition properties for a wide range of compounds, including quite large peptide derivatives. A suggested change of about five order of magnitudes in the distribution coefficient can explain the "lock in" mechanism of brain-targeting delivery systems.     

What is "special" about face perception?

There is growing evidence that face recognition is "special" but less certainty concerning the way in which it is special. The authors review and compare previous proposals and their own more recent hypothesis, that faces are recognized "holistically" (i.e., using relatively less part decomposition than other types of objects). This hypothesis, which can account for a variety of data from experiments on face memory, was tested with 4 new experiments on face perception. A selective attention paradigm and a masking paradigm were used to compare the perception of faces with the perception of inverted faces, words, and houses. Evidence was found of relatively less part-based shape representation for faces. The literatures on machine vision and single unit recording in monkey temporal cortex are also reviewed for converging evidence on face representation. The neuropsychological literature is reviewed for-evidence on the question of whether face representation differs in degree or kind from the representation of other types of objects.     

Shielding evaluation of a medical linear accelerator vault in preparation for installing a high-dose rate 252Cf remote afterloader

In support of the effort to begin high-dose rate 252Cf brachytherapy treatments at Tufts-New England Medical Center, the shielding capabilities of a clinical accelerator vault against the neutron and photon emissions from a 1.124 mg 252Cf source were examined. Outside the clinical accelerator vault, the fast neutron dose equivalent rate was below the lower limit of detection of a CR-39 etched track detector and below 0.14 +/- 0.02 muSv h(-1) with a proportional counter, which is consistent, within the uncertainties, with natural background. The photon dose equivalent rate was also measured to be below background levels (0.1 muSv h(-1)) using an ionisation chamber and an optically stimulated luminescence dosemeter. A Monte Carlo simulation of neutron transport through the accelerator vault was performed to validate measured values and determine the thermal-energy to low-energy neutron component. Monte Carlo results showed that the dose equivalent rate from fast neutrons was reduced by a factor of 100,000 after attenuation through the vault wall, and the thermal-energy neutron dose equivalent rate would be an additional factor of 1000 below that of the fast neutrons. Based on these findings, the shielding installed in this facility is sufficient for the use of at least 5.0 mg of 252Cf.     

新型磷酸二酯酶Ⅳ抑制剂Ariflo 对内皮素-1诱发离体人子宫平滑肌收缩的影响

目的:研究选择性磷酸二酯酶(phosphodiesterase, PDE) Ⅳ抑制剂Ariflo 对内皮素-1 (endothelin-1,ET-1)诱发的非妊娠人子宫平滑肌收缩的影响。方法:累积给药法观察药物对离体平滑肌收缩的作用。结果:Ariflo 可降低子宫平滑肌自主收缩的收缩频率及收缩幅度(pD₂ =7.90), 且对ET-1 (3 ×10^-8 mol·L^-1)诱发的子宫平滑肌收缩具有浓度依赖性抑制作用(pD₂ =7.40), 作用强度与Rolipram 相似。结论:Ariflo 对ET-1 诱发的离体人子宫平滑肌的收缩具有显著抑制作用, 提示在临床上有缓解痛经的作用。