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51.
Gamma-methylene-10-deazaaminopterin (MDAM), a unique dihydrofolate reductase inhibitor, has demonstrated antitumor activity against a broad spectrum of human solid tumors in preclinical studies. A novel reversed-phase, ion-pair high-performance liquid chromatography (HPLC) assay that uses fluorescence detection has been developed to quantitate levels of MDAM and its major metabolite, 7-hydroxy-gamma-methylene-10-deazaaminopterin (7-OH-MDAM), in human plasma. The recovery of MDAM and 7-OH-MDAM from plasma was >97% by a simple one-step deproteinization process using tetrabutylammonium bromide (TBABr) and methanol. MDAM and 7-OH-MDAM remained stable in plasma over a 28-day test period at ambient temperatures, and neither compound was light-sensitive. The limit of quantitation was 0.005 microM for both MDAM and 7-OH-MDAM. This assay has been found to be simple, sensitive and reproducible in determining plasma concentrations of MDAM and 7-OH-MDAM in patients with solid cancers in a phase I trial.  相似文献   
52.
We have cloned and characterized the white gene of Anopheles albimanus. Comparison of the deduced amino acid sequence of this white gene with its homologs from six species of Diptera show that the An. albimanus gene is most similar to the white gene of An. gambiae (92% identity). A spontaneous white-eyed mutant An. albimanus was caused by an approximately 10 kb insertion into a CT dinucleotide repeat region of intron 2 of the white locus. The flanks of this insertion are long (at least 400 bp), nearly perfect inverted terminal repeat sequences. This cloned white gene should be useful as a marker for germ line transformation of An. albimanus.  相似文献   
53.
The regulation by neuropeptide Y of alpha2-adrenoceptors in the nucleus tractus solitarii was evaluated in the adult normotensive Wistar Kyoto rat and the adult spontaneously hypertensive rat. The microinjection of a submaximal dose of l-noradrenaline (800 pmol in 50 nl) alone into the nucleus tractus solitarii produced a significant reduction in the mean arterial blood pressure in either strain. The threshold dose (1 pmol in 50 nl) of neuropeptide Y(1-36) for the vasodepressor response in the Wistar Kyoto rat was five times higher than that (0.2 pmol in 50 nl) in the spontaneously hypertensive rat. Furthermore, neuropeptide Y(1-36) at 0.2 pmol in 50 nl could significantly counteract the vasodepressor response to l-noradrenaline (800 pmol in 50 nl) in the spontaneously hypertensive rat, but not in the Wistar Kyoto rat, in which 1 pmol in 50 nl of neuropeptide Y(1-36) must be employed to counteract the vasodepressor response to l-noradrenaline (800 pmol in 50 nl), although the vasodepressor responses are of a similar magnitude. The in situ hybridization and quantitative receptor autoradiographical experiments showed that the alpha2A-adrenoceptor messenger RNA levels and the B(max) value of the alpha2-adrenoceptor agonist [3H]p-aminoclonidine binding sites measured in the nucleus tractus solitarii of the spontaneously hypertensive rat were substantially lower than those in the Wistar Kyoto rat. The quantitative receptor autoradiographical results were consistent with the cardiovascular results and showed that in the spontaneously hypertensive rat, neuropeptide Y(1-36) at 1 nM led to a significant increase in the K(d) value of [3H]p-aminoclonidine binding sites. In the Wistar Kyoto rat, neuropeptide Y(1-36) produced this effect only at 10 nM. The present study provides evidence for an increase of the potency of neuropeptide Y(1-36) to antagonistically modulate alpha2-adrenoceptors in the nucleus tractus solitarii of the spontaneously hypertensive rat. This enhanced antagonistic action may partly be related to a reduction in the number of alpha2A-adrenoceptors in the nucleus tractus solitarii of the spontaneously hypertensive rat, since a decrease has been observed in the alpha2A-adrenoceptor messenger RNA levels and the alpha2-adrenoceptor binding sites in the spontaneously hypertensive rat. This increased potency of neuropeptide Y(1-36) to antagonize alpha2-adrenoceptor function in the nucleus tractus solitarii of the spontaneously hypertensive rat may contribute to the development of high blood pressure in this hypertensive strain.  相似文献   
54.
This paper presents the first detailed analysis of the artefacts from the Mousterian level G3 at Vindija Cave and a revision of the artefact analysis for the early Upper Paleolithic levels (j, i) at Velika Pe?ina, both in Croatia. Combined with an assessment of the artefacts from the crucial G1 level at Vindija, results of these analyses are used to argue that the combination of Middle and Upper Paleolithic elements in the upper G complex at Vindija is not necessarily the result of geological mixing but may well represent a natural cultural assemblage. Some Upper Paleolithic elements are possibly derived from the local Mousterian, while others result from extraneous cultural influences into this region. Interestingly, currently available radiocarbon dates indicate that Neanderthals (Vindija level G1) and early modern humans (Velika Pe?ina) were penecontemporaneous in this region at ca. 33 ka, or perhaps somewhat earlier if the radiocarbon dates are taken as minimum age estimates. Therefore some Upper Paleolithic tools associated with the Vindija G1 Neanderthals, such as bone points, may result from imitation of or trade with early modern people. While there is external influence on the development of the early Upper Paleolithic in this region, it exhibits a unique character which does not conform to that of classic Western or Central European Aurignacian.  相似文献   
55.
56.
Pregnancy is thought to have an ameliorating effect on endometriosis, inducing a state of quiescence. We report a case of ruptured endometriotic cyst in pregnancy successfully treated by laparoscopic ovarian cystectomy. Our patient subsequently progressed uneventfully to deliver a healthy baby girl at term. Laparoscopic ovarian cystectomy in pregnancy, even with ruptured cysts, appeared to be safe in trained hands with similar benefits of reduced post-operative morbidity.  相似文献   
57.
It is unclear whether the intracardial immune reactivity after heart transplantation influences the peripheral immunological status (activation or nonresponsiveness) of the patient. Co-stimulation and activation-induced cell death (AICD) or apoptosis play an important role in determining the balance between lymphocyte reactivity and nonreactivity. Therefore, we studied the expression of co-stimulatory molecules and the process of apoptosis in biopsies of human heart allografts, using immunohistochemistry. Although a normal expression of co-stimulatory molecules on antigen-presenting cells was observed, the expression of their counter-structures on T cells was absent. This may be due to chronic T cell activation, which can lead to the induction of apoptosis via the Fas/Fas ligand pathway. In the infiltrates, a considerable percentage of the lymphocytes, but not the macrophages, were apoptotic. Apoptosis was confirmed by DNA fragmentation analysis. Increased numbers of Bax-expressing versus decreased numbers of Bcl2-expressing lymphocytes in comparison with normal lymphoid tissue confirmed a imbalance in favor of apoptosis. Apoptosis was biased towards CD4+ T cells (65.7% versus 26.6% in CD8+ T cells). Fas was expressed on most of the infiltrating cells. Fas ligand expression was also observed, not only on most of the T cells but also on all macrophages. Because macrophages were often detected in close contact with T cells, they may play a role in T cell regulation via the Fas/Fas ligand pathway. This study indicates that, during rejection, not only is tissue damage induced by infiltrating T cells, but also the infiltrating lymphocytes themselves are actively down-regulated (eg, AICD) by one another and by macrophages in the infiltrate. This regulatory process may affect the immunological status of the patient after heart transplantation.  相似文献   
58.
I examine trends in single mothers' living arrangements using data from the 1970-1995 Current Population Surveys. I create a consistent trend by correcting a coding problem that stemmed from the misidentification of children living in multigenerational households before 1984. Revised estimates show that the number of single mothers in each of these years was undercounted by 200,000-300,000. All of these women were subfamily heads living with their parents, and the problem occurred disproportionately among teens and black women. The uncorrected trend falsely indicates a large increase in the share of single mothers living with their parents. In reality, there was little change in the percentage of single mothers living in this arrangement over the time period. However, the data indicate a large increase in the rate of cohabitation and a comparable decline in the rate of living independently among this population.  相似文献   
59.
Transurethral electrovaporization of the prostate (TVP) is a new minimally invasive procedure for treatment of enlargement of prostate. Between April 1996 and September 1997, TVP was carried out in 109 cases with symptoms of lower urinary tract obstruction. A Stortz spike electrode and a Stortz vapor cutting electrode were used for vaporization electrodes. Efficacy parameters evaluated included International Prostate Symptom Score, peak uroflow and postvoid residual volume. By September 1997, 32 cases (spike electrode) and 33 cases (vapor cutting electrode) could be followed up and evaluated. They have shown both subjective and objective voiding improvement. The improvements in subjective symptom scores and objective voiding parameters were not significantly different between the two electrode groups. Early complications included urinary retention, intraoperative burn, stress incontinence, blood transfusion and postoperative hemorrhage. Late complications included urethral stricture, bladder neck contracture and bladder stone. TVP was found to have several advantages, particularly minimal bleeding and the low incidence of postoperative morbidity. The technique is simple and symptoms improve at an early stage following surgery. This study demonstrates that TVP is a safe and effective modality for treatment of BPH. However, long-term studies with larger numbers of patients are needed.  相似文献   
60.
In summary, the National Database Committee's Audit and Validation Subcommittee is working to maximize the data completeness and quality of the STS National Database. Toward this end, we welcome your suggestions for improvement.  相似文献   
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