大丁草中抗菌活性成分的研究Ⅳ

从秋季采收的菊科植物大丁草Gerbera anandria(L.)Sch Bip.全草中共分出十三种成分。本文报道其中三个新化合物的结构鉴定.它们分别是3,8-dihydroxy-4-methoxy-coumarin(ⅪⅩ),3,8-dihydroxy-4-methoxy-2-oxo-2 H-1-benzopyran-5-carboxylic acid(ⅩⅦ),和5,8-dihydroxy-7-(4-hydroxy-5-methyl-coumarin-3-)-coumarin(ⅩⅪ)。     

Total radical trapping antioxidant potential (TRAP) and exercise

The relationship between physical activity, physical fitness and total radical trapping antioxidant potential (TRAP) was examined in the Northern Ireland Health and Activity Survey. This was a cross-sectional population study (n = 1600) using a two-stage probability sample of the population. TRAP was calculated using the sum of the individual serum antioxidant concentrations (urate, protein thiols, ascorbate, alpha tocopherol and bilirubin) multiplied by their respective stoichiometric values. Physical fitness was determined by estimation of VO2max by extrapolation from submaximal oxygen uptake, and physical activity was recorded by computer-assisted interview. Mean serum TRAP concentrations were significantly higher in males (653 +/- 8.2 mumol/l, mean +/- SEM) compared to females (564 +/- 8.0 mumol/l) (p < 0.0001). Both male and female smokers had significantly lower TRAP values than non-smokers (males p < 0.0001, females p = 0.02). In females, there was a positive relationship of TRAP with age (p < 0.001) and body mass index (p < 0.001) but a negative relationship with physical fitness (p < 0.05). The known beneficial effects of exercise and activity do not appear to be directly mediated through increased antioxidant status.      

Members of the glutathione and ABC-transporter families are associated with clinical outcome in patients with diffuse large B-cell lymphoma

Standard chemotherapy fails in 40% to 50% of patients with diffuse large B-cell lymphoma (DLBCL). Some of these failures can be salvaged with high-dose regimens, suggesting a role for drug resistance in this disease. We examined the expression of genes in the glutathione (GSH) and ATP-dependent transporter (ABC) families in 2 independent tissue-based expression microarray datasets obtained prior to therapy from patients with DLBCL. Among genes in the GSH family, glutathione peroxidase 1 (GPX1) had the most significant adverse effect on disease-specific overall survival (dOS) in the primary dataset (n = 130) (HR: 1.68; 95% CI: 1.26-2.22; P < .001). This effect remained statistically significant after controlling for biologic signature, LLMPP cell-of-origin signature, and IPI score, and was confirmed in the validation dataset (n = 39) (HR: 1.7; 95% CI: 1.05-2.8; P = .033). Recursive partitioning identified a group of patients with low-level expression of GPX1 and multidrug resistance 1 (MDR1; ABCB1) without early treatment failures and with superior dOS (P < .001). Overall, our findings suggest an important association of oxidative-stress defense and drug elimination with treatment failure in DLBCL and identify GPX1 and ABCB1 as potentially powerful biomarkers of early failure and disease-specific survival.     

A retrospective case-control study of the use of hormone-related supplements and association with breast cancer

Hormone-related supplements (HRS), many of which contain phytoestrogens, are widely used to manage menopausal symptoms, yet their relationship with breast cancer risk has generally not been evaluated. We evaluated whether use of HRS was associated with breast cancer risk, using a population-based case-control study in 3 counties of the Philadelphia metropolitan area consisting of 949 breast cancer cases and 1,524 controls. Use of HRS varied significantly by race, with African American women being more likely than European American women to use any herbal preparation (19.2% vs. 14.7%, p=0.003) as well as specific preparations including black cohosh (5.4% vs. 2.0%, p=0.003), ginseng (12.5% vs. 7.9%, p<0.001) and red clover (4.7% vs. 0.6%, p<0.001). Use of black cohosh had a significant breast cancer protective effect (adjusted odds ratio 0.39, 95% CI: 0.22-0.70). This association was similar among women who reported use of either black cohosh or Remifemin (an herbal preparation derived from black cohosh; adjusted odds ratio 0.47, 95% CI: 0.27-0.82). The literature reports that black cohosh may be effective in treating menopausal symptoms, and has antiestrogenic, antiproliferative and antioxidant properties. Additional confirmatory studies are required to determine whether black cohosh could be used to prevent breast cancer.     

Use of risk-reducing surgeries in a prospective cohort of 1,499 BRCA1 and BRCA2 mutation carriers

Inherited mutations in BRCA1 or BRCA2 (BRCA1/2) confer very high risk of breast and ovarian cancers. Genetic testing and counseling can reduce risk and death from these cancers if appropriate preventive strategies are applied, including risk-reducing salpingo-oophorectomy (RRSO) or risk-reducing mastectomy (RRM). However, some women who might benefit from these interventions do not take full advantage of them. We evaluated RRSO and RRM use in a prospective cohort of 1,499 women with inherited BRCA1/2 mutations from 20 centers who enrolled in the study without prior cancer or RRSO or RRM and were followed forward for the occurrence of these events. We estimated the age-specific usage of RRSO/RRM in this cohort using Kaplan–Meier analyses. Use of RRSO was 45 % for BRCA1 and 34 % for BRCA2 by age 40, and 86 % for BRCA1 and 71 % for BRCA2 by age 50. RRM usage was estimated to be 46 % by age 70 in both BRCA1 and BRCA2 carriers. BRCA1 mutation carriers underwent RRSO more frequently than BRCA2 mutation carriers overall, but the uptake of RRSO in BRCA2 was similar after mutation testing and in women born since 1960. RRM uptake was similar for both BRCA1 and BRCA2. Childbearing influenced the use of RRSO and RRM in both BRCA1 and BRCA2. Uptake of RRSO is high, but some women are still diagnosed with ovarian cancer before undergoing RRSO. This suggests that research is needed to understand the optimal timing of RRSO to maximize risk reduction and limit potential adverse consequences of RRSO.     

用正糖钳夹试验评估基础胰岛素类似物作用特点的研究

健康人通过体内胰岛素的分泌调节，可以保持正常的血糖水平。各种外源性胰岛素制剂在代谢过程上总是尽可能地模拟内源性胰岛素的分泌动力学。理想的外源性基础胰岛素制剂可以模拟健康人的基础胰岛素分泌，以致使用者可以恢复两餐之间和夜间正常生理情况下的血浆胰岛素水平。     

Granulocyte colony-stimulating factor crosses the placenta and stimulates fetal rat granulopoiesis

We studied the effect of recombinant human granulocyte colony- stimulating factor (rhG-CSF) administration to pregnant rats upon fetal and neonatal myelopoiesis. Pregnant rats were treated with rhG-CSF twice daily for 2, 4, and 6 days before parturition. rhG-CSF crossed the placenta and reached peak fetal serum concentrations 4 hours after administration. Peak fetal serum levels were 1,000-fold lower than levels detected in the dam. Hematopoietic effects of rhG-CSF were assessed by cytologic analysis of the newborn blood, spleen, bone marrow, thymus, and liver. White blood cell counts were increased twofold to fourfold in newborns. This increase was due to circulating numbers of polymorphonuclear cells (PMN). rhG-CSF induced a myeloid hyperplasia in the newborn marrow consisting of immature and mature myeloid cells in the day-2 and day-4 treated pups. Bone marrow of pups treated for 6 days contained mostly hyper-segmented PMN with little or no increase in myeloid precursors. An increase in the number of postmitotic (PMN, bands, and metamyelocytes) and mitotic (promyeloblasts, myeloblasts, and metamyeloblasts) myeloid cells in the spleen of neonates was observed. No change was detected in splenic lymphocytes or monocytes. No effect of rhG-CSF was noted in the newborn liver or thymus. These results demonstrate that maternally administered rhG-CSF crosses the placenta and specifically induces bone marrow and spleen myelopoiesis in the fetus and neonate. The significant myelopoietic effects of rhG-CSF at low concentrations in the fetus suggest an exquisite degree of developmental sensitivity to this cytokine and may provide enhanced defense mechanisms to the neonate.