10-propargyl-10-deazaaminopterin: an antifolate with activity in patients with previously treated non-small cell lung cancer.

PURPOSE: 10-propargyl-10-deazaaminopterin (PDX) has superior antitumor efficacy in mouse xenograft models, likely attributable to increased uptake by the RFC-1 folate transporter and greater intracellular polyglutamylation. In a previous Phase I trial, stomatitis was the dose-limiting (and only clinically significant) toxicity of PDX. The recommended Phase II dose was 150 mg/m(2) i.v. every 2 weeks. Responses observed in patients with non-small cell lung cancer (NSCLC) in the Phase I trial prompted this Phase II trial. EXPERIMENTAL DESIGN: Patients had stage IIIB or IV NSCLC and either no previous chemotherapy or progression after initial response or stable disease to one previous chemotherapy regimen. Initially, PDX was administered at a dose of 150 mg/m(2) every 2 weeks. However, to decrease the frequency of stomatitis, the last 10 patients were treated at a dose of 135 mg/m(2). We planned to correlate PDX effects with folate and homocysteine levels and the expression of genes associated with folate transport and polyglutamylation. RESULTS: Thirty-nine patients were enrolled, 38 of whom were evaluable for response. Four patients had confirmed, major objective responses (10% based on intent to treat, 95% confidence interval 3-25) lasting 4, 9, 12, and 15 months. Twelve patients (31%) had stable disease. The median survival was 13.5 months. The predicted 1- and 2-year survival rates were 56 and 36%, respectively. Two patients (5%) suffered grade 4 stomatitis, and 6 (15%) had grade 3. No clinically significant myelosuppression occurred. No correlation between homocysteine or serum folate levels and severity of stomatitis was observed. Area under the curve (calculated using a limited sampling model) correlated with mucositis grade. A trend was noted between folate transporter expression and treatment effect. CONCLUSIONS: The broad applicability of this new antifolate with limited toxicity and proven efficacy in NSCLC encourage further development of this compound. Several trials are now underway combining PDX with other chemotherapeutic agents and testing its efficacy in other cancers.     

Mentoring in Clinical‐Translational Research: A Study of Participants in Master's Degree Programs

Research projects in translational science are increasingly complex and require interdisciplinary collaborations. In the context of training translational researchers, this suggests that multiple mentors may be needed in different content areas. This study explored mentoring structure as it relates to perceived mentoring effectiveness and other characteristics of master''s‐level trainees in clinical‐translational research training programs. A cross‐sectional online survey of recent graduates of clinical research master''s program was conducted. Of 73 surveys distributed, 56.2% (n = 41) complete responses were analyzed. Trainees were overwhelmingly positive about participation in their master''s programs and the impact it had on their professional development. Overall the majority (≥75%) of trainees perceived they had effective mentoring in terms of developing skills needed for conducting clinical‐translational research. Fewer trainees perceived effective mentoring in career development and work‐life balance. In all 15 areas of mentoring effectiveness assessed, higher rates of perceived mentor effectiveness was seen among trainees with ≥2 mentors compared to those with solo mentoring (SM). In addition, trainees with ≥2 mentors perceived having effective mentoring in more mentoring aspects (median: 14.0; IQR: 12.0–15.0) than trainees with SM (median: 10.5; IQR: 8.0–14.5). Results from this survey suggest having ≥2 mentors may be beneficial in fulfilling trainee expectations for mentoring in clinical‐translational training.     

In vitro study on the transfer of volatile oil components

The following volatile oils were tested in vitro: chamomile (Matricaria recutica L.), peppermint (Mentha piperita L.) and sage (Salvia officinalis L.) to obtain information on which components of volatile oils or minerals are able to pass through the membranes under different conditions. The transfer of chamomile and peppermint oil from aqueous volatile oil to the stomach (pH=1.1) and then to the plasma (pH=7.5) was studied, and the transfer of sage oil through the skin (from pH=5.5 to pH=7.5) was examined. The transfer of some components was more favorable than that of others. The transfer of chamomile oil was faster to buffer pH=1.1 than from buffer pH=1.1 to buffer pH=7.5 and most of the components, except for chamazulene, passed through the membranes. In the case of peppermint the components went through the membranes in the first 15 min although the main components mostly remained in the initial solution. The sage oil transferred showed the same characteristics as the starting oil. A small amount of metal present in the volatile oils also passed through the membranes. The transfer of metals varied, depending on the time, type of the oil, metal quality and the conditions applied.     

Multiply resistant mutants of Enterobacter cloacae selected by beta-lactam antibiotics

Mutants of Enterobacter cloacae, selected in vitro with ceftriaxone, ceftazidime, carumonam, or aztreonam, fell into several distinct classes. Three mutants highly resistant to nearly all beta-lactam antibiotics were stably derepressed for beta-lactamase production. Although no other changes could be detected, virulence in a mouse septicemia model was decreased in two of these mutants. One mutant, 908-Ssi, showed selectively decreased susceptibility to ampicillin and cefotetan. A change in beta-lactamase expression was thought to be responsible for this. Alterations in the production of two outer membrane proteins with molecular sizes of 36.5 and 39 kilodaltons were responsible for multiple antibiotic resistance in two mutants, both of which acquired a low level of resistance to beta-lactam antibiotics. Whereas one of the mutants, AMA-R, simultaneously acquired resistance to chloramphenicol and trimethoprim, the other, AZT-R, became hypersusceptible to these and other hydrophobic agents. Both strains had drastically reduced virulence in mice.     

枸杞子多糖、黄芪多糖、刺五加多糖和鼠伤寒杆菌内毒素多糖对LAK活性的调节作用

采用~(125)IUdR释放法测定了不同浓度的枸杞子多糖、黄芪多糖、刺五加多糖及鼠伤寒杆菌内毒素多糖对不同剂量rIL-2激活的杀伤细胞(LAK)抗肿瘤活性的影响,发现4种多糖在一定浓度条件下均可在体外增强LAK活性。枸杞子多糖在0.01～0.1mg·ml~(-1)、黄芪多糖和刺五加多糖在0.01mg·ml~(-1)时增强作用最显著(P<0.001),内毒素多糖在0.0001～0.1μg·ml~(-1)时可增强LAK活性,在0.0001μg·ml~(-1)时最显著。4种多糖浓度过低或过高则不能增强,甚至抑制LAK活性。     

Activation of Erk mitogen-activated protein kinase proteins by vascular serotonin receptors

We previously demonstrated that 5-hydroxytryptamine 2A (5-HT 2A ) receptor-mediated rat arterial contraction was dependent on activation of tyrosine kinases, including mitogen-activated protein kinase (MAPK) kinase. In the current study, we examined arterial smooth muscle for the presence of serotonin (5-hydroxytryptamine, 5-HT) 5-HT 1B, 5-HT 1D, 5-HT 1F, 5-HT 2A, 5-HT 2B, and 5-HT 7 receptor mRNA and hypothesized that, if present, activation of these receptors would stimulate the extracellular signal-regulated kinase (Erk) MAPK pathway and an Erk MAPK-dependent contraction. RT-PCR analyses of rat aortic smooth muscle cells, cultured and fresh, indicated the presence of 5-HT 1B, 5-HT 1D, 5-HT 1F, 5-HT 2A, 5-HT 2B, and 5-HT 7 receptor mRNA. The 5-HT 1B agonists RU24969 and CGS12066B, 5-HT 1B/1D/1F receptor agonist sumatriptan, and 5-HT 2B receptor agonist BW723C86 (10(-9) - 10(-4) M ) did not contract the aorta, nor did the 5-HT 7 receptor antagonist LY215840 leftward shift 5-HT-induced contraction. The 5-HT 1E/1F receptor agonist BRL54443 induced contraction, but this was abolished by the 5-HT 2A/2C receptor antagonist ketanserin (10 nM ); contraction was not observed with a different 5-HT 1F receptor agonist, LY344864. 5-HT and alpha-methyl-5-HT produced a concentration-dependent increase in Erk MAPK activity in cultured aortic smooth muscle cells and in aorta contracted with these agonists. All other agonists were inactive; a high concentration of BRL54443 (10 microM ) stimulated Erk MAPK activation (150% basal). Thus, while mRNA and possibly protein for multiple 5-HT receptors are present in aortic smooth muscle, only the 5-HT 2A receptor plays a significant role in directly modulating contractility and activating the Erk MAPK pathway.     

Dose-ranging study to delineate the additive antihypertensive effect of guanabenz and captopril

This open crossover study in eight hypertensive patients defined a possible additive effect of oral guanabenz and captopril and determined a safe and effective dose range. Each group of four patients received placebo followed by ascending doses (on alternate days) of either guanabenz (2, 4, 8 mg) or captopril (6.25, 12.5, 25 mg) as initial monotherapy and were subsequently crossed over to the alternate monotherapy. Guanabenz and captopril were given concomitantly in increasing doses--the highest dose for both groups being 8 mg guanabenz/25 mg captopril. When guanabenz and captopril were given concomitantly, blood pressure decreased, both from the values during placebo administration and from the lead-in values recorded before each dose. Mean supine systolic and diastolic blood pressures after combination therapy decreased significantly (P less than .05) in a dose-related manner at most evaluations. The authors conclude that guanabenz and captopril have an additive effect when administered in combination to patients with hypertension.     

Spontaneous eyelid expansion after full thickness eyelid resection and direct closure

BACKGROUND/AIMS: Direct closure of eyelid defects gives excellent functional results but is usually restricted to defects measuring less than a quarter of the eyelid length for fear of distorting the palpebral aperture and compromising lid function. The authors have used direct closure in larger defects. The aim of this study was to establish the effects of direct closure of full thickness eyelid margin defects under tension on the palpebral aperture dimensions. METHODS: A consecutive series of patients who had undergone one eyelid, full thickness lid resection repaired by direct closure were identified and invited to have both eyes photographed. The palpebral apertures of both eyes were measured from the photographs by a masked observer. The amount of eyelid resected was recorded from the operation notes. The unoperated palpebral aperture was used as the control. The result were analysed using a paired samples t test. RESULTS: The photographs of 18 patients were included in the analysis. The mean width of excised full thickness lid tissue was 15 mm (range 7-26 mm). The mean vertical palpebral aperture height was 9.2 (SD 1.4) mm in the operated eye as opposed to 9.3 (SD 1.2) mm in the non-operated eye. The mean horizontal palpebral aperture width was 26.1 (SD 1.9) mm in the operated eye as opposed to 26.4 (SD 1.8) mm in the non-operated eye. There was no statistically significant difference between the operated and unoperated horizontal and vertical palpebral measurements. CONCLUSIONS: Direct closure of large full thickness eyelid defects is possible in selected patients with excellent functional and cosmetic results. Eyelid tissue expansion occurs spontaneously following direct eyelid defect closure under tension, restoring the palpebral aperture dimensions.