Heme synthesis by copper-deficient cells was investigated to elucidate the nature of the defect in intracellular iron metabolism. Iron uptake from transferrin by copper-deficient reticulocytes was 52% of normal, and the rate of heme synthesis was 33% of normal. Hepatic mitochondria isolated from copper-deficient animals were deficient in cytochrome oxidase activity and failed to synthesize heme from ferric iron (Fe III) and protoporphyrin at the normal rate. The rate of heme synthesis correlated with the cytochrome oxidase activity. Heme synthesis from Fe(III) and protoporphyrin by normal mitochondria was enhanced by succinate and inhibited by malonate, antimycin A, azide, and cyanide. It is proposed that an intact electron transport system is required for the reduction of Fe(III), thereby providing a pool of ferrous iron (Fe II) for protoheme and heme a synthesis. 相似文献
The 9p21 locus has been deleted at a high frequency in a wide variety of tumors. Recently, two genes, p16INK4A and p15INK4B (also called MTS1 and MTS2), have been localized in close proximity at the 9p21 locus, encoding cyclin-dependent kinases 4/6 inhibitors of relative molecular mass 16 kD and 15 kD, respectively and also found to be deleted at a high frequency in tumor cell lines. We analyzed p16INK4A and p15INK4B genes in 178 cases of primary leukemias including 81 cases of chronic lymphocytic leukemia (CLL), seven of hairy cell leukemia (HCL), seven of chronic myelogenous leukemia (CML), 43 of acute myelogenous leukemia (AML), 27 of acute lymphoblastic leukemia (ALL), and 13 of myelodysplastic syndrome (MDS) by Southern blot analyses. The ALL cases showed a relatively high frequency of homozygous deletions (22%, 6 of 27) at the p16INK4A gene locus. Interestingly, of the six cases with p16INK4A homozygous deletions, only three showed homozygous deletions at the p15INK4B gene. In 81 CLL patients, we detected one homozygous and five heterozygous deletions at both the p16INK4A and p15INK4B genes and two heterozygous deletions at the p16INK4A gene alone. Deletion of these two genes in AML cases is relatively low (9%). We did not detect deletions in any of the MDS, HCL, and CML cases examined. Sequence analyses of p16INK4A gene of six CLL cases with heterozygous deletion at this locus showed a 27-bp deletion at the splice acceptor site of intron 1 in one case and changes in the coding sequence in three other cases. The data presented in this report showed that (1) p16INK4A and p15INK4B genes are preferentially deleted homozygously in ALL and heterozygously in CLL cases with frequent mutation in the second allele, and (2) p16INK4A gene appears to be more frequently deleted than p15INK4B gene. 相似文献
Primary care is increasingly interested in the identification of frailty, as it selects the target population for integrated care. However, instruments for the identification of frailty specifically validated for use in primary care are scarce. This study developed the Easycare Two-step Older persons Screening (Easycare-TOS), which provides a valid, efficient, and pragmatic screening procedure to identify frail older people.
Aim
This paper aims to describe the development of the Easycare-TOS and the data from the pilot studies.
Design and setting
Observational pilot study in seven academic GP practices in and around Nijmegen, The Netherlands.
Method
The Easycare-TOS was developed in a cyclic process with the input of stakeholders. In every cycle, the requirements were first defined, then translated into a prototype that was tested in a pilot study. The Easycare-TOS makes optimal use of prior knowledge of the GP, and the professionals’ appraisal is decisive in the frailty decision, instead of a cut-off score. Further, it considers aspects of frailty, as well as aspects of the care context of the patient.
Results
The pilot data have shown that after step 1, two-thirds of the patients do not need further assessment, because they are judged as not frail, based on prior knowledge of the GP. The overall prevalence of frailty in this pilot study is 24%. Most professionals who participated in the pilot studies considered the time investment acceptable and the method to be of added value.
Conclusion
The Easycare-TOS instrument meets the predefined efficiency, flexibility, and acceptability requirements for use as an identification instrument for frailty in primary care. 相似文献
The endovenous revolution has accelerated the development of new techniques and devices for the treatment of varicose veins. The ClariVein® mechanochemical ablation device offers tumescentless treatment with a rotating ablation tip that can theoretically become stuck in tissue. We present the first report of retrograde stripping of the small saphenous vein without anaesthesia following attempted use of the ClariVein® device, without adverse sequelae. 相似文献
Objective: To evaluate the role of an open access heart failure service based at a teaching hospital for the diagnosis and treatment optimisation of patients with heart failure in the community and to identify measures that may further enhance the effectiveness of such a service.
Subjects: 963 patients with suspected heart failure seen over an eight year period referred by their general practitioners to the cardiology department at a district general hospital.
Main outcome measures: Presence or absence of left ventricular systolic dysfunction (LVSD) (left ventricular ejection fraction < 50% on echocardiography), and determination of the risk factors and predictors of LVSD.
Results: The majority of the patients were women (60% v 40%) and elderly (mean age 68.8 years). On echocardiography, only 30.8% were found to have LVSD. Patients were more likely to have LVSD if they were men (42.3% v 23.1%, p < 0.001, relative risk (RR) 1.8), were > 60 years of age (33.5% v 20.8%, p < 0.001, RR 1.6), or had a history of diabetes (49.4% v 29.1%, p < 0.001, RR 1.7), ischaemic heart disease (36.5% v 29.1%, p = 0.04, RR 1.3), or atrial fibrillation (52.6% v 27.8%, p < 0.001, RR 1.9). An abnormal ECG (48.4% v 19.5%, p < 0.001, RR 2.5) and cardiothoracic ratio > 0.5 on chest radiograph (44.3% v 17.8%, p < 0.001, RR 2.5) were found to be good predictors of LVSD. A normal ECG (negative predictive value 80.5%) and a cardiothoracic ratio of < 0.5 (negative predictive value 82.2%) can be used as baseline measures to identify patients with lower risk of developing LVSD (combined negative predictive value 87.9%).
Conclusions: An open access heart failure clinic is effective for the diagnosis and management of chronic heart failure in community based patients. The presence of risk factors and simple baseline tests can be used to identify patients with LVSD in the community. The introduction of a protocol based on these findings into a referral system can improve the efficiency and cost effectiveness of such a service.
Cyclooxygenase-2 (COX-2, PTGS2) is an enzyme involved in the synthesis of prostaglandins and thromboxanes, which are regulators of biologic processes such as inflammation, cell proliferation and angiogenesis. COX-2 over-expression was reported in many (pre) malignant tissues, but data strongly vary and seem to depend on the methodology used.
Methods
Normal colorectal mucosa and paired cancerous tissue from 60 patients with colorectal cancer was investigated for the levels of COX-2 mRNA by real-time quantitative Polymerase Chain Reaction (qPCR). COX-2 levels were expressed relative to either: tissue weight or levels of the housekeeping genes beta-2 microglobulin (B2M) and glyceraldehyde-3-phosphate dehydrogenase (GAPDH).
Results
COX-2 mRNA levels, normalized with respect to tissue weight or mRNA levels of the housekeeping genes B2M or GAPDH, were over-expressed in 80%, 70% and 40% of the colorectal tumor tissues, as compared to the paired adjacent normal colorectal mucosa samples, respectively. Highest mRNA COX-2 ratios tumor/normal were measured when expressed per mg tissue (mean ratio 21.6). When normalized with respect to the housekeeping genes B2M or GAPDH, mean tumor/normal ratios were 16.1 and 7.5, respectively.
Conclusion
Expression of COX-2 mRNA levels per mg tissue is most simple in comparison to normalization with respect to the housekeeping genes B2M or GAPDH. Levels of COX-2 mRNA are found over-expressed in almost 80% of the colorectal tumors, compared to paired adjacent normal colorectal mucosa, suggesting a role of COX-2 as a potential biomarker for cancer risk, whereas inhibitors of COX-2 could be of value in chemoprevention of colon cancer. 相似文献
Impaired trophoblast invasion is associated with pregnancy disorders such as early pregnancy loss and preeclampsia. There is evidence to suggest that the consumption of caffeine during pregnancy may increase the risk of pregnancy loss; however, little is known about the direct effect of caffeine on normal trophoblast biology. Our objectives were to examine the effect of caffeine on trophoblast migration and motility after stimulation with epidermal growth factor (EGF) and to investigate the intracellular signaling pathways involved in this process. Primary first-trimester extravillous trophoblasts (EVT) and the EVT-derived cell line SGHPL-4 were used to study the effect of caffeine on EGF-stimulated cellular motility using time-lapse microscopy. SGHPL-4 cells were further used to study the effect of caffeine and cAMP on EGF-stimulated invasion of fibrin gels. The influence of caffeine and cAMP on EGF-stimulated intracellular signaling pathways leading to the activation of Akt were investigated by Western blot analysis. Caffeine inhibits both EGF-stimulated primary EVT and SGHPL-4 cell motility. EGF stimulation activates phosphatidylinositol 3-kinase, and Akt and caffeine inhibit this activation. Although cAMP inhibits both motility and invasion, it does not inhibit the activation of Akt, indicating that the effects of caffeine seen in this study are independent of cAMP. Further investigation indicated a role for mammalian target of rapamycin complex 2 (mTORC2) as a target for the inhibitory effect of caffeine. In conclusion, we demonstrate that caffeine inhibits EGF-stimulated trophoblast invasion and motility in vitro and so could adversely influence trophoblast biology in vivo. 相似文献
Overactive bladder (OAB) has a multifactorial aetiology, and for some women symptoms may be associated with chronic urothelial inflammation secondary to bacterial colonisation. One marker of such inflammation may be urinary nerve growth factor (NGF). We hypothesised that for women with OAB and urothelial inflammation, urinary NGF would be reduced following antibiotic therapy.
Methods
Women with overactive bladder and urodynamic diagnosis of detrusor overactivity who were refractory to anticholinergics, and had histological evidence of urothelial inflammation were treated with a 6-week course of rotating antibiotics. Urinary NGF was measured by ELISA before and after treatment. Three-day bladder diaries, the Patients’ Perception of Intensity of Urgency Scale, the King’s Health Questionnaire and the Patients’ Perception of Bladder Condition questionnaire were used to assess subjective and objective outcomes of therapy.
Results
Thirty-nine women with refractory DO were recruited. The NGF levels decreased significantly after antibiotic therapy (Wilcoxon signed rank test; p?=?0.015). There were significant improvements in daytime frequency, nocturia and urgency (p?<?0.05), and 74 % of women reported improvement in perception of their bladder condition.
Conclusions
Urinary NGF is responsive to antibiotic therapy. Women with refractory overactive bladder and elevated NGF may benefit from antibiotic treatment. 相似文献