Citations

Purpose This phase I study was undertaken to define the toxicity, pharmacokinetics, pharmacodynamics, maximum tolerated dose (MTD), and clinical activity of CI-1040, a small-molecule inhibitor of the dual-specificity kinases MEK(mitogen-activated protein kinase kinase) -1 and MEK2 , in patients with advanced malignancy. Patients and Methods CI-1040 was tested in multiple daily dosing frequencies administered for 21 days repeated every 28 days leading ultimately to continuous administration, and effect of food on absorption was tested. Single dose and steady-state pharmacokinetics were assessed during cycle 1 and phosphorylated extracellular receptor kinase (pERK) levels were assessed in WBCs and also in tumor tissue from selected patients. Results Seventy-seven patients received CI-1040 at dose levels ranging from 100 mg QD to 800 mg tid. Grade 3 asthenia was dose limiting at the highest dose level tested, 800 mg tid administered with food. Ninety-eight percent of all drug-related adverse events were grade 1 or 2 in severity; most common toxicities included diarrhea, asthenia, rash, nausea, and vomiting. Plasma concentrations of CI-1040 and its active metabolite, PD 0184264, increased in a less than dose proportional manner from 100 to 800 mg QD. Administration with a high-fat meal resulted in an increase in drug exposure. The MTD and recommended phase II dose was 800 mg BID administered with food. Sixty-six patients were assessable for response. One partial response was achieved in a patient with pancreatic cancer and 19 patients (28%) achieved stable disease lasting a median of 5.5 months (range, 4 to 17 months). Inhibition of tumor pERK (median, 73%; range, 46% to 100%) was demonstrated in 10 patients. Conclusion CI-1040 was well tolerated at 800 mg BID administered with food. Both target suppression and antitumor activity were demonstrated in this phase I study.

Purpose To determine, in a randomized comparison, whether the addition of paclitaxel to etoposide and cisplatin improves the time to progression and overall survival in patients with extensive small-cell lung cancer (SCLC) compared with standard etoposide and cisplatin and to compare the regimens' toxicity. Patients and Methods Eligible patients (N = 587) with untreated extensive SCLC were randomly assigned to receive either cisplatin 80 mg/m2 on day 1 and etoposide 80 mg/m2 on days 1 through 3 administered every 3 weeks for six cycles (EP) or cisplatin 80 mg/m2 on day 1, paclitaxel 175 mg/m2 over 4 hours on day 1, and etoposide 80 mg/m2 on days 1 to 3 followed by recombinant human granulocyte colony-stimulating factor on days 4 to 18 administered every 3 weeks for six cycles (PET). Results Reporting of demographics, response, and survival included 565 patients, of whom 282 were randomly assigned to receive EP and 283 were assigned to receive PET. Overall response rates were 68% for the EP arm and 75% for the PET arm. Median failure-free survival time was 5.9 months for the EP arm and 6 months for the PET arm (P = .179). Median overall survival time was 9.9 months for patients on EP and 10.6 months for patients on PET (P = .169). Toxic deaths occurred in 2.4% of the patients on EP and 6.5% of patients on PET. Conclusion PET did not improve the time to progression or survival in patients with extensive SCLC compared with EP alone and was associated with unacceptable toxicity.

ABSTRACT Exposure of ciprofloxacin- and cefepime-susceptible Pseudomonas aeruginosa isolates to increasing concentrations of ciprofloxacin selected for ciprofloxacin resistance in 26/27 and cefepime nonsusceptibility in 7/27 isolates. Exposure of the isolates to increasing concentrations of cefepime selected for cefepime nonsusceptibility in 20/27 isolates but not for ciprofloxacin resistance.

Neurofibrillary tangles composed of hyperphosphorylated, aggregated tau are a common pathological feature of tauopathies, including Alzheimer's disease. Abnormal phosphorylation of tau by kinases or phosphatases has been proposed as a pathogenic mechanism in tangle formation. To investigate whether kinase inhibition can reduce tauopathy and the degeneration associated with it in vivo , transgenic mice overexpressing mutant human tau were treated with the glycogen synthase kinase-3 (GSK-3) inhibitor lithium chloride. Treatment resulted in significant inhibition of GSK-3 activity. Lithium administration also resulted in significantly lower levels of phosphorylation at several epitopes of tau known to be hyperphosphorylated in Alzheimer's disease and significantly reduced levels of aggregated, insoluble tau. Administration of a second GSK-3 inhibitor also correlated with reduced insoluble tau levels, supporting the idea that lithium exerts its effect through GSK-3 inhibition. Levels of aggregated tau correlated strongly with degree of axonal degeneration, and lithium-chloride-treated mice showed less degeneration if administration was started during early stages of tangle development. These results support the idea that kinases are involved in tauopathy progression and that kinase inhibitors may be effective therapeutically.

ABSTRACT DNA from 101 specimens containing herpes simplex virus (HSV) produced atypical intermediate melting curves compared with those expected for HSV type 1 or HSV type 2 subsequent to real-time PCR. Nucleic acid sequence analysis of amplified target DNA revealed 1- or 3-bp polymorphisms in the probe region which allowed designation of these viruses as HSV genotype 1 or HSV genotype 2. These two subpopulations of HSV were also identified as HSV genotype 1 or HSV genotype 2 using another commercially available PCR method. Amplified HSV target DNA producing intermediate melting curves could be designated as HSV genotype 1 or HSV genotype 2 without performing sequencing or another PCR method with 96/101 (95%) specimens by adding known intermediate HSV DNA characteristic for the two subpopulations as controls.

ABSTRACT A total of 563 specimens (234 dermal and 329 genital swabs) from patients suspected of having herpes simplex virus (HSV) infections were processed using two different extraction methods (the MagNA Pure LC system and the swab extraction tube system [SETS]); HSV DNA was amplified by LightCycler PCR. HSV DNA was detected in 157 of 563 specimens (27.9%) processed by the MagNA Pure LC system and in 179 of 563 specimens (31.8%) processed by SETS ( P < 0.0001). There was no specimen processed by the MagNA Pure LC extraction method that was positive only for HSV DNA. Of 157 specimens positive by both methods, HSV DNA copy levels were higher (using cycle crossover points [cycle threshold { C T }]) with SETS (mean C T , 25.9 cycles) than with the MagNA Pure LC system (mean C T , 32.0 cycles) ( P < 0.0001). The time to process 32 samples was longer with the MagNA Pure LC extraction system (90 min) than with SETS (35 min). HSV DNA extraction using SETS is faster, less expensive, and more sensitive than the MagNA Pure LC system and could replace the latter for the laboratory diagnosis of HSV infections using LightCycler PCR.

Immature dendrites extend many actin-rich filopodial structures that can be replaced by synapse-containing dendritic spines as the neuron matures. The large GTPase dynamin-3 (Dyn3) is a component of the postsynapse in hippocampal neurons but its function is undefined. Here, we demonstrate that a specific Dyn3 variant (Dyn3baa) promotes the formation of immature dendritic filopodia in cultured neurons. This effect is dependent upon Dyn3 GTPase activity and a direct interaction with the F-actin-binding protein cortactin. Consistent with these findings, Dyn3baa binds to cortactin with a 200% higher affinity than Dyn3aaa, a near identical isoform that does not induce dendritic filopodia when expressed in cultured neurons. Finally, levels of Dyn3baa-encoding mRNA are tightly regulated during neuronal maturation and are markedly upregulated during synaptogenesis. Together, these findings provide the first evidence that an enhanced interaction between a specific Dyn3 splice variant and cortactin modulate actin-membrane dynamics in developing neurons to regulate the morphogenesis of dendritic spines.

ABSTRACT Transforming growth factor‐β (TGF‐β) is the single most important cytokine promoting renal fibrogenesis. p21‐activated kinase‐2 (PAK2) and activa‐ tion of abelson nonreceptor tyrosine kinase (c‐abl) have been shown recently to be smad‐independent, fibro‐ blast‐specific targets downstream of the activated TGF‐β receptor. In the current study we show that in cultured NRK49F‐renal fibroblasts (but not in tubular or mesangial cells) TGF‐β similarly activates PAK2 as well as c‐abl and induces cell proliferation. Inhibition of the c‐abl kinase with imatinib mesylate prevents increased proliferation after TGF‐β addition without affecting PAK2. These in vitro findings were extended to rats with unilateral obstructive nephropathy, a dis‐ ease model of TGF‐β‐driven renal fibrogenesis. In obstructed kidneys, PAK2 and c‐abl activity were in‐ creased but only c‐abl activation was blocked by ima‐ tinib. Treatment with imatinib did not prevent renal interstitial infiltration of macrophages or phosphoryla‐ tion and nuclear translocation of smad2/3 in ob‐ structed kidneys. In contrast, imatinib substantially inhibited an increase in the number of interstitial fibroblasts and myofibroblasts and reduced the expres‐ sion and interstitial accumulation of collagen type III, collagen type IV and fibronectin. These findings indi‐ cate that TGF‐β‐induced activation of the nonreceptor c‐abl tyrosine kinase regulates fibroblast proliferation and, by this means, is a costimulatory signal in TGF‐β‐ dependent renal fibrogenesis. Inhibition of c‐abl activ‐ ity with imatinib mesylate ameliorates experimental renal fibrosis in rats.—Wang, S., Wilkes, M. C., Leof, L. B., Hirschberg, R. Imatinib mesylate blocks a non‐ Smad TGF‐β pathway and reduces renal fibrogenesis in vivo. FASEB J. 19, 1‐11 (2005)