急性淋巴细胞白血病最新治疗策略(下)

4分子治疗分析肿瘤细胞中的分子遗传性变异及后天变异的方法正在快速成熟起来。这些方法通常涉及基因组学、转录特征性识别及蛋白质组学,有利于更深入地了解ALL的发病机理,使用于临床评估的靶向治疗全面发展。最终,这些层出不穷的新技术将营造出一个全新的个性化分子医学时代,创造出效果更好而毒性更低的治疗方案。尽管治疗方案均显示了药物介入控制细胞周期进程、基因转录、细胞运动、凋亡及细胞代谢信号通路的可行性(图1),但针对ALL的分子治疗情况(表1)仍差强人意。我们将从众多正处于临床前期或早期临床研究的分子治疗方案中,选择出那…     

Relationship between shock attenuation and stride length during running at different velocities

The purpose of the study was to investigate the characteristics of shock attenuation during high-speed running. Maximal running speed was identified for each subject [n=8 males, 25 (SD 4.6) years; 80 (8.9) kg; 1.79 (0.06) m] as the highest speed that could be sustained for about 20 s on a treadmill. During testing, light-weight accelerometers were securely mounted to the surface of the distal antero-medial aspect of the leg and frontal aspect of the forehead. Subjects completed running conditions of 50, 60, 70, 80, 90, and 100% of their maximal speeds with each condition lasting about 20 s. Stride length, stride frequency, leg and head peak impact acceleration were recorded from the acceleration profiles. Shock attenuation was analyzed by extracting specific sections of the acceleration profiles and calculating the ratio of head to leg power spectral densities across the 10–20 Hz frequency range. Both stride length and stride frequency increased across speeds (P<0.05) and were correlated with running speed (stride length r=0.92, stride frequency r=0.89). Shock attenuation increased about 20% per m·s^–1 across speeds (P<0.05), which was similar to the 17% increase in stride length per m·s^–1. Additionally, shock attenuation was correlated with stride length (r=0.71) but only moderately correlated with stride frequency (r=0.40) across speeds. It was concluded that shock attenuation increased linearly with running speed and running kinematic changes were characterized primarily by stride length changes. Furthermore, the change in shock attenuation was due to increased leg not head peak impact acceleration across running speeds. Electronic Publication     

Noninvasive cardiovascular markers of acoustically induced arousal from non-rapid-eye-movement sleep

STUDY OBJECTIVES: Changes in cardiovascular measures such as heart rate (HR) and pulse transit time (PTT) have been advocated as sensitive markers of autonomic arousal from sleep. In animal studies, alerting stimuli produce particularly marked skin vascular responses. We hypothesized that changes in skin vascular conductance would provide more sensitive markers of autonomic arousal during sleep compared to central cardiovascular response measures such as HR and PTT. DESIGN: Cardiovascular responses to auditory-induced arousals were recorded during overnight sleep studies. SETTING: Sleep disorders unit in a 270-bed teaching hospital. PARTICIPANTS: Eleven young healthy male subjects. INTERVENTIONS: Throughout ovemight sleep studies, auditory tones (5-second duration, 54-90 decibels, 22-56 per subject) were presented during non-rapid-eye-movement sleep. Beat-by-beat HR, PTT, laser-Doppler fingertip skin blood flow (SBF) and finger and ear photoplethysmogram pulse wave amplitudes (PWA) were measured in the 20 seconds preceding and 30 seconds following each tone and compared to control measurements obtained during 50-second periods of recording with no stimulus (no tone, 6-22 per subject). Electroencephalographic (EEG) arousals were scored according to standard criteria (American Sleep Disorders Association) into no discemible, 3- to 10-second duration, or 10- to 15-second duration arousals. Poststimulus cardiovascular measurements were expressed as a percentage of the prestimulus mean and response magnitudes quantified from peak responses and the area under the poststimulus response curve. The ability of each cardiovascular response measure to discriminate EEG arousals (EEG changes lasting more than 3 seconds) was assessed from the area under the receiver operating characteristic (ROC) curve. MEASUREMENTS AND RESULTS: There were no significant changes in any cardiovascular parameter during control recordings. In contrast to all other parameters, finger PWA and SBF decreased following tones that produced no discernible EEG arousal (P < 0.05). A significant HR rise and decreases in all cardiovascular measures occurred with greater than 3-second arousals, with longer duration arousals generally exhibiting larger responses. Conventional EEG arousals (greater than 3 seconds) were relatively poorly detected from HR responses (ROC area HR rise 0.80 +/- 0.04) compared to changes in SBF (0.85 +/- 0.02), PTT (0.85 +/- 0.03) and finger PWA (0.90 +/- 0.01). CONCLUSIONS: Decreases in skin vascular conductance (finger PWA and SBF) provide sensitive markers of autonomic arousal during sleep. They are at least as sensitive as PTT for detecting conventionally scored EEG arousals and may be more sensitive in detecting "subcortical" arousals.     

Clinical features, epidemiology, antimicrobial resistance, and exotoxin genes (including that of Panton-Valentine leukocidin) of gentamicin-susceptible methicillin-resistant Staphylococcus aureus (GS-MRSA) isolated at a paediatric teaching hospital in New South Wales, Australia

AIMS: To describe the epidemiological, clinical, and laboratory features of gentamicin-susceptible methicillin-resistant Staphylococcus aureus (GS-MRSA) seen at a paediatric teaching hospital. METHODS: Patients from whom GS-MRSA was isolated between 1 January 2001 and 31 December 2002 were enrolled. Retrospective chart review was performed. Susceptibility testing was performed with the Vitek2 system; PCR confirmed methicillin resistance. Phage typing and pulsed field gel electrophoresis (PFGE) was performed (utilising MLST/SCCmec-defined control strains). PCR detection of tst, luk-PV, and entA-entE was performed. RESULTS: Eighty-five per cent of all Staphylococcus aureus isolates during the study period were methicillin-sensitive, and 15% were MRSA (9% GS-MRSA, 6% gentamicin resistant-MRSA). 100 GS-MRSA infections in 98 children were identified: 59 cases of skin/soft tissue, four bone and joint, four surgical site infections, three pneumonia, eight other types, and 22 represented colonisation. Ninety-nine isolates were non-multidrug resistant, but 17 strains were resistant to erythromycin, 7 to tetracyclines, 12 to ciprofloxacin, 11 to fusidic acid, 1 each to rifampicin and mupirocin. 44 isolates were Oceania strain (ST30-MRSA-IV), 20 were Queensland strain (ST93-MRSA-IV), ten were UK EMRSA-15 (ST22-MRSA-IV), eight were WA MRSA-1 (ST1-MRSA-IV), two were WA MRSA-5 (ST8-MRSA-IV), one was WA MRSA-2 (ST78slv-MRSA-IV), one was WA MRSA-15 (ST59-MRSA-IV), and the remainder were sporadics. Twenty patients were Pacific Islanders, of whom 12 had the Oceania strain; ten were Aboriginal, of whom eight had the Queensland strain. Sixty-eight isolates possessed luk-PV, including all Queensland strains and 91% of Oceania strains. Enterotoxin genes were detected in 25% of the isolates, and tst was detected in four isolates. CONCLUSIONS: GS-MRSA is a significant paediatric problem in New South Wales: two minority groups are over-represented, multiple epidemic strains were detected, most community strains possess luk-PV, and many isolates are multidrug resistant.     

Delivery of a hammerhead ribozyme specifically down-regulates the production of fibrillin-1 by cultured dermal fibroblasts

The hammerhead ribozyme is a small catalytic RNA molecule. Potential hammerhead ribozymes that possess a catalytic domain and flanking sequence complementary to a target mRNA can cleave in trans at a putative cleavage site within the target molecule. We have investigated the potential of hammerhead ribozymes to down-regulate the product of the fibrillin-1 gene (FBN1). Fibrillin is a 347 kDa glycoprotein that is a major constituent of the elastin-associated microfibrils. Mutations in the FBN1 gene are responsible for Marfan syndrome (MFS), a common systemic disorder of the connective tissue. Many FBN1 mutations responsible for MFS appear to act in a dominant-negative fashion, raising the possibility that reduction of the amount of product from the mutant FBN1 allele might be a valid therapeutic approach for MFS. A trans-acting hammerhead ribozyme (FBN1-RZ1) targeted to the 5' end of the human FBN1 mRNA has been designed and synthesized, and shown to cleave its target efficiently in vitro. FBN1-RZ1 cleavage is magnesium dependent and efficient at both 37 and 50 degrees C. Delivery of the FBN1-RZ1 ribozyme into cultured dermal fibroblasts, by receptor- mediated endocytosis of a ribozyme-transferrin-polylysine complex, specifically reduces both cellular FBN1 mRNA and the deposition of fibrillin in the extracellular matrix. These results suggest that the use of hammerhead ribozymes is a valid approach to the study of fibrillin gene expression and possibly to the development of a therapeutic approach to MFS.      

PROGNOSTIC SIGNIFICANCE OF THE CO-EXPRESSION OF p53 AND c-erbB-2 PROTEINS IN BREAST CANCER

The immunohistochemical expression of p53 and c-erbB-2 gene proteins was examined in a series of 130 breast adenocarcinomas. This study intended to investigate whether the frequency of the altered expression of the tumour suppressor gene p53 and the overexpression of the oncogene c-erbB-2 in breast cancer tissue cells correlated with other variables known to affect the biological behaviour of these tumours and the overall survival of the patients (median follow-up time: 6 years). The expression of p53 protein and c-erbB-2 gene product was evaluated immunohistochemically. Expression of p53 protein was detected in 30 (23 per cent) of the neoplasms examined, while 26 (20 per cent) out of the 130 cases demonstrated positive c-erbB-2 immunoreactivity. There was a statistically significant association between p53 protein expression and primary tumour size, lymph node involvement, and oestrogen receptor positivity. The incidence of c-erbB-2 positivity was significantly correlated with high tumour grade, axillary node invasion, large tumour size, and the absence of steroid receptors. p53 immuno-expression was clearly associated with c-erbB-2 protein overexpression. Concomitant p53 and c-erbB-2 positive immunolabelling, which emerged in 14 out of the 130 cases (10·7 per cent), was clearly associated with high grade, large size, positive nodal status, ductal infiltrating (NOS) histological type, and low values of progesterone receptors. Overall survival of patients was not significantly related to the immunoreactivity of either p53 or c-erbB-2 considered separately, whereas there was a clearly significant trend to worse overall prognosis in cancers with double p53/c-erbB-2 positive phenotype. The simultaneous immunodetection of p53/c-erbB-2 appears to have greater negative prognostic relevance than their separate expression.     

Germline mutation in BRAF codon 600 is compatible with human development: de novo p.V600G mutation identified in a patient with CFC syndrome

Champion KJ, Bunag C, Estep AL, Jones JR, Bolt CH, Rogers RC, Rauen KA, Everman DB. Germline mutation in BRAF codon 600 is compatible with human development: de novo p.V600G mutation identified in a patient with CFC syndrome. BRAF, the protein product of BRAF, is a serine/threonine protein kinase and one of the direct downstream effectors of Ras. Somatic mutations in BRAF occur in numerous human cancers, whereas germline BRAF mutations cause cardio‐facio‐cutaneous (CFC) syndrome. One recurrent somatic mutation, p.V600E, is frequently found in several tumor types, such as melanoma, papillary thyroid carcinoma, colon cancer, and ovarian cancer. However, a germline mutation affecting codon 600 has never been described. Here, we present a patient with CFC syndrome and a de novo germline mutation involving codon 600 of BRAF, thus providing the first evidence that a pathogenic germline mutation involving this critical codon is not only compatible with development but can also cause the CFC phenotype. In vitro functional analysis shows that this mutation, which replaces a valine with a glycine at codon 600 (p.V600G), leads to increased ERK and ELK phosphorylation compared to wild‐type BRAF but is less strongly activating than the cancer‐associated p.V600E mutation.     

A 37‐year‐old Menkes disease patient—Residual ATP7A activity and early copper administration as key factors in beneficial treatment

Menkes disease (MD) is a lethal disorder characterized by severe neurological symptoms and connective tissue abnormalities; and results from malfunctioning of cuproenzymes, which cannot receive copper due to a defective intracellular copper transporting protein, ATP7A. Early parenteral copper‐histidine supplementation may modify disease progression substantially but beneficial effects of long‐term treatment have been recorded in only a few patients. Here we report on the eldest surviving MD patient (37 years) receiving early‐onset and long‐term copper treatment. He has few neurological symptoms without connective tissue disturbances; and a missense ATP7A variant, p.(Pro852Leu), which results in impaired protein trafficking while the copper transport function is spared. These findings suggest that some cuproenzymes maintain their function when sufficient copper is provided to the cells; and underline the importance of early initiated copper treatment, efficiency of which is likely to be dependent on the mutant ATP7A function.