Case of the month: May 1998--a patient with HIV infection and multiple cranial neuritis

A 36-year old male with a three year history of HIV infection and more recently, CMV retinitis, had several episodes of polyradiculitis with severe bilateral leg pain and urinary retention which resolved slowly over several months. He then presented with high fevers and severe dysphagia with dehydration. Examination showed oral thrush, dyarthric speech and mild memory impairment. Fundoscopic exam showed CMV retinitis and HIV retinopathy. Further examination revealed other cranial nerve signs and leg weakness. MRI scans showed several contrast enhancing abnormalities of cranial nerve roots. The patient died from massive barium aspiration. At autopsy the brain showed multiple CMV cranial neuritis, CMV polyradiculitis and CMV ventriculo-ependymitis. While spinal nerve root involvement by CMV may occur in up to 1% of AIDS patients, involvement of cranial nerves is unusual and CMV infection of multiple cranial nerves is distinctly rare.     

Pollen-wall proteins: quantitative cytochemistry of the origins of intine and exine enzymes in Brassica oleracea

Simultaneous coupling methods for detection of acid phosphatase and non-specific esterase produce a coloured reaction product that is quantitatively related to enzyme content in freeze-sectioned Brassica pollen and tapetal cells. The intine-located acid phosphatase has 2 periods of synthesis: the first in late vacuolate period, associated with the completion of deposition of the intine polysaccharides; the second during pollen maturation, apparently reflecting cytoplasmic synthesis, Esterase activity accumulates in the tapetal cells until dissolution at early maturation period, when there is a dramatic rise in pollen-wall esterase activity, reflecting the transfer from tapetum to exine cavities. These quantitative studies confirm the gametophytic and sporophytic origins of the intine and exine proteins.     

模拟自然风的空调装置实验研究

为使空调装置送风更加接近自然风提高其送风热舒适性,通过变速控制器将自然风作为控制信号控制变速风机的方法,研制出可模拟自然风送风的空调装置。对此装置在电机变速和恒速两种工况下的出风特性进行测试,并对其送风的波动规律、湍流度、概率分布、自相关性及频谱特性等紊动特性进行计算分析。计算结果表明:当控制信号为自然风时,此装置能产生与自然风相似的的动态风,其紊动特性与控制信号有很好的一致性,其送风在低频区域能量较高,高频区域能量较低,频谱曲线变化剧烈;当装置电机恒速运行时,其出风频谱曲线变化平缓。研究表明:采用自然风为输入信号控制变速控制器可使空调送风具有自然风的紊动特性。     

电缆半导电屏蔽层中导电离子析出模型分析

中低压电力电缆主绝缘的水树现象是造成电缆故障的一个很重要的因素,在温度和高电场等外界条件共同作用下,电缆半导电屏蔽层中含有的游离导电离子析出后在电缆主绝缘表面形成水树现象的起始点。通过对半导电屏蔽试样水煮得到的数据进行分析,建立扩散模型,利用Fick第二扩散方程对该模型进行解析,得到t时刻试样中导电离子的浓度分布并与导电离子的析出试验数据相符。     

Treatment of refractory and relapsed acute myelogenous leukemia with combination chemotherapy plus the multidrug resistance modulator PSC 833 (Valspodar)

A potential mechanism of chemotherapy resistance in acute myeloid leukemia (AML) is the multidrug resistance (MDR-1) gene product P-glycoprotein (P-gp), which is often overexpressed in myeloblasts from refractory or relapsed AML. In a multicenter phase II clinical trial, 37 patients with these poor risk forms of AML were treated with PSC 833 (Valspodar; Novartis Pharmaceutical Corporation, East Hanover, NJ), a potent inhibitor of the MDR-1 efflux pump, plus mitoxantrone, etoposide, and cytarabine (PSC-MEC). Pharmacokinetic (PK) interactions of etoposide and mitoxantrone with PSC were anticipated, measured in comparison with historical controls without PSC, and showed a 57% decrease in etoposide clearance (P =.001) and a 1.8-fold longer beta half-life for mitoxantrone in plasma (P <.05). The doses of mitoxantrone and etoposide were substantially reduced to compensate for these interactions and clinical toxicity and in Cohort II were well tolerated at dose levels of 4 mg/m2 mitoxantrone, 40 mg/m2 etoposide, and 1 g/m2 C daily for 5 days. Overall, postchemotherapy marrow hypoplasia was achieved in 33 patients. Twelve patients (32%) achieved complete remission, four achieved partial remission, and 21 failed therapy. The PK observations correlated with enhanced toxicity. The probability of an infectious early death was 36% (4 of 11) in patients with high PK parameters for either drug versus 5% (1 of 20) in those with lower PK parameters (P =.04). P-gp function was assessed in 19 patients using rhodamine-123 efflux and its inhibition by PSC. The median percentage of blasts expressing P-gp was increased (49%) for leukemic cells with PSC-inhibitable rhodamine efflux compared with 17% in cases lacking PSC-inhibitable efflux (P =.004). PSC-MEC was relatively well tolerated in these patients with poor-risk AML, and had encouraging antileukemic effects. The Eastern Cooperative Oncology Group is currently testing this regimen versus standard MEC chemotherapy in a phase III trial, E2995, in a similar patient population.     

Increased in vivo collagen synthesis and in vitro cell proliferative effect of glycolic acid

BACKGROUND: Glycolic acid treatment is believed to reverse the photoaging process by increasing collagen synthesis in the skin. However, this effect has not been clearly defined even though alpha hydroxy acid products are used extensively. OBJECTIVE: This study aimed to define the primary effect of glycolic acid on collagen synthesis that may be achieved by functional activation or proliferation of fibroblasts. METHODS: Glycolic acid treatment was compared in vivo with lactic acid (hairless mice) and in vitro to malic acid (normal human skin fibroblast culture) with controls. To find the functional activation of fibroblasts, Northern blot assay for type I collagen synthesis with histometric analysis (in vivo) was performed. Cell proliferation assay (MTT) with procollagen type I C-peptide (PICP) enzyme immunoassay and radioisotope ([3H]proline) incorporated collagen production from cultured fibroblasts were determined. RESULTS: The in vivo collagen mRNA expression with histometric analysis revealed greater collagen synthesis by glycolic acid compared with lactic acid and control. In vitro cell proliferative effect of glycolic and greater amount of collagen production showed a steady increase in a dose-dependent manner. CONCLUSION: Both in vivo and in vitro, glycolic acid treatment increased the production of collagen and fibroblast proliferation. These effects may be the mechanism by which glycolic acid reverses the process of photoaging.     

Survival of patients with advanced urothelial cancer treated with cisplatin-based chemotherapy

The aim of the present retrospective study was to assess long-term survival after cisplatin-based chemotherapy in 398 patients with advanced urothelial transitional cell carcinoma (TCC) treated at seven international oncological units. Various combinations of cisplatin, methotrexate, vinblastine (or vincristine) and doxorubicin were used. The complete response rate according to the WHO criteria was 17%. Partial responses were obtained in 42% of the patients. The overall cancer-related 2 year and 5 year survival rates were 21% and 11% respectively. Based on multivariate analyses, a good prognosis group could be identified comprising patients with a good performance status with disease confined to lymph nodes (14%) or patients with T4b disease only. These patients had a 28% 5 year survival rate, which, in part, has to be related to post-chemotherapy consolidation treatment in patients with pelvis-confined disease (radiotherapy, 26%; total cystectomy, 11%). Fifteen patients died of chemotherapy-related complications and in 16% of the patients toxicity led to discontinuation of treatment. Modern cisplatin-based chemotherapy leads to long-term survival and cure of selected patients with advanced urothelial transitional cancer. In routine clinical practice, chemotherapy should be offered to good prognosis patients; those presenting with a good performance status and a non-metastasising T4b tumour or with metastases confined to lymph nodes. Post-chemotherapy consolidation treatment by surgery or radiotherapy should always be considered. Such chemotherapy requires oncological expertise in order to avoid unnecessary toxicity.