Multidetector-row computed tomography and magnetic resonance imaging of atherosclerotic lesions in human ex vivo coronary arteries

In the present study, we tested the ability of multidetector-row computed tomography (MDCT) and magnetic resonance imaging (MRI) to identify and retrospectively characterize atherosclerotic lesions in human ex vivo coronary arteries. Thirteen ex vivo hearts were studied with MDCT and MRI. MDCT-images were obtained with an isotropic voxel size of 0.6mm(3). MR images were obtained with an in-plane resolution of 195 microm and 3mm slice thickness. All images were matched with histopathology sections. For both modalities, the sensitivity for the detection of any atherosclerotic lesion was evaluated, and a retrospective analysis of plaque morphology according to criteria defined by the American Heart Association (AHA) was performed. At histopathology, 28 atherosclerotic lesions were found. 21 and 23 of these lesions were identified by MDCT and MRI, respectively. Both modalities detected a small number of false-positive lesions. After retrospective matching with histopathology, MDCT as well as MRI were able to differentiate typical morpholocigal features for fatty, fibrous or calcified plaque components. Using the information presented in this study, in vivo coronary artery wall imaging using MDCT as well as MRI could be facilitated and supported for future investigations on this subject.     

High Fluctuation Between Anticoagulants,Frequent Off-Label Dosing,and No Difference Concerning Outcomes: Results of a Real-Life Cohort Study

BackgroundRecently published studies indicated a high proportion of patients taking direct oral anticoagulants (DOACs) are off-label under- or overdosed. The present study aimed at investigating whether off-label dosages are corrected over time and whether off-label doses are associated with differences in bleeding rates, ischemic stroke, or venous thromboembolism.MethodsIn this retrospective cohort study, patients presenting to our emergency department between January 1 and December 31, 2018, with therapeutic oral anticoagulation were included (ie, vitamin-K antagonists [VKAs], rivaroxaban, apixaban, edoxaban, and dabigatran) and follow-up for a maximum of 2 years until December 31, 2019, was made. Detailed chart reviews were performed for each case concerning characteristics, indication, bleeding complications, or changes in the used substance or dosage.ResultsWe reviewed 2588 consultations of 1228 patients receiving therapeutic oral anticoagulation. During the maximum follow-up period of 2 years vitamin K antagonists and rivaroxaban lost the largest proportions in favor of apixaban. The overall distribution of dosage correctness remained almost unimproved (correct dosing in 62.5%, underdosing in 23.6%, coverdosing in 13.9%).The corresponding outcomes did not differ with respect to bleeding events, ischemic stroke, or venous thromboembolism among various anticoagulants as well as between correct and off-label doses.ConclusionsA rising proportion of existing oral anticoagulation regimes was changed to apixaban, while the proportion of off-label dosages of all oral anticoagulants remained stable. No difference in bleeding rates, de novo strokes, or thromboembolisms was found between anticoagulants as well as between correct and off-label doses.     

Peripheral blood progenitor cells mobilized by chemotherapy plus granulocyte-colony stimulating factor accelerate both neutrophil and platelet recovery after high-dose VP16, ifosfamide and cisplatin

Summary. We report on the chemotherapy plus granulocyte colony-stimulating factor (G-CSF) induced mobilization of peripheral blood progenitor cells (PBPCs) and their impact on haematopoietic recovery following high-dose chemotherapy. Twenty-four patients with advanced solid tumours or lymphomas received standard-dose chemotherapy with VP16, ifosfamide and cisplatin (VIP) followed by filgrastim (G-CSF; 5 μg/kg s.c. daily for 14 d) for the prevention of chemotherapy induced neutropenia and for the simultaneous mobilization of PBPCs. Maximal numbers of progenitors of different lineages were reached at day 11 (range 9–14) after VIP chemotherapy. A median of 0·415 × 10⁹/1 CD34⁺ cells (range 0·11–1·98), 9000 CFU-GM/ml (range 2800–17700). 3500 BFU-E/ml (range 400–10800) and 200 CFU-GEMM/ml (range 0–4400) were recruited. One single apheresis yielded a median of 1·6 × 10⁸ mononuclear cells/kg (range 0·2–5·4) or 5·4 × 10⁶ CD34⁺ cells/kg body weight (range 0·2–24·2). Fourteen patients who showed at least a partial remission after two cycles of the standard-dose chemotherapy regimen were subjected to high-dose VIP chemotherapy (cumulative doses of 1500 mg/m² VP16, 12 g/m² ifosfamide and 150 mg/m² cisplatin) with or without PBPC support. The first six patients were treated with growth factors only (IL-3/GM-CSF) and did not receive PBPCs, whereas the following eight patients were supported with PBPCs in addition to IL-3 and GM-CSF. Neutrophil recovery as well as platelet recovery were significantly faster in patients receiving PBPCs with a median of 6·5 d below 0·1 × 10⁹ neutrophils/1 and 3 d below 20 × 10⁹ platelets/1 as compared to 10·5 d and 8 d in control patients receiving growth factors only. The accelerated platelet recovery in patients supported with PBPCs might be explained—in the absence of detectable colony-forming units megakaryocyte—by the presence of glycoprotein IIb/IIIa⁺, non-proliferating endomitotic megakaryocytic precursor cells within G-CSF mobilized PBPCs. Our data demonstrate that chemotherapy plus G-CSF mobilized PBPCs accelerate both neutrophil and platelet recovery after high-dose VIP chemotherapy in patients with solid tumours or lymphomas.     

Targeting of heat shock protein 32 (Hsp32)/heme oxygenase-1 (HO-1) in leukemic cells in chronic myeloid leukemia: a novel approach to overcome resistance against imatinib

Resistance toward imatinib and other BCR/ABL tyrosine kinase inhibitors remains an increasing clinical problem in the treatment of advanced stages of chronic myeloid leukemia (CML). We recently have identified the heat shock protein 32 (Hsp32)/heme oxygenase-1 (HO-1) as a BCR/ABL-dependent survival molecule in CML cells. We here show that silencing Hsp32/HO-1 in CML cells by an siRNA approach results in induction of apoptosis. Moreover, targeting Hsp32/HO-1 by either pegylated zinc protoporphyrine (PEG-ZnPP) or styrene maleic acid-micelle-encapsulated ZnPP (SMA-ZnPP) resulted in growth inhibition of BCR/ABL-transformed cells. The effects of PEG-ZnPP and SMA-ZnPP were demonstrable in Ba/F3 cells carrying various imatinib-resistant mutants of BCR/ABL, including the T315I mutant, which exhibits resistance against all clinically available BCR/ABL tyrosine kinase inhibitors. Growth-inhibitory effects of PEG-ZnPP and SMA-ZnPP also were observed in the CML-derived human cell lines K562 and KU812 as well as in primary leukemic cells obtained from patients with freshly diagnosed CML or imatinib-resistant CML. Finally, Hsp32/HO-1-targeting compounds were found to synergize with either imatinib or nilotinib in producing growth inhibition in imatinib-resistant K562 cells and in Ba/F3 cells harboring the T315I mutant of BCR/ABL. In summary, these data show that HO-1 is a promising novel target in imatinib-resistant CML.     

Screening for colorectal cancer: the cost to find an advanced adenoma

OBJECTIVE: Cancer Care Ontario has recommended a program to screen for colorectal cancer using fecal occult blood testing (FOBT). Patients who test positive on FOBT will require further investigation. We examined the cost of finding an advanced adenoma in these patients using four different strategies. METHODS: Using decision analysis software (DATA 3.5, TreeAge Software, Boston, MA), we considered four strategies for evaluating patients referred for a positive FOBT: 1) flexible sigmoidoscopy to the splenic flexure, 2) flexible sigmoidoscopy with air contrast barium enema (ACBE), 3) virtual colonoscopy, and 4) colonoscopy. If an adenoma was found in any of the first three methods, colonoscopy and polypectomy were performed. An advanced adenoma was defined as a villous adenoma, tubular adenoma > or = 10 mm, high grade dysplasia, or cancer. Values for probabilities, test characteristics and costs ($CDN) were estimated from a MEDLINE literature review, local costs, and OHIP fee codes. Patients with adenomas identified as well as direct medical costs from a third party payer perspective were calculated. RESULTS: Assuming a probability of adenoma of 16.9%, the cost for each strategy (compared to no investigation) was as follows: flexible sigmoidoscopy to the splenic flexure, $226; flexible sigmoidoscopy with ACBE, $424; virtual colonoscopy, $597; and colonoscopy, $387. The cost to clear a patient of adenoma(s) was $1,930, $2,840, $3,681, and $2,290, respectively. Despite being most cost-effective, the sigmoidoscopy strategy was predicted to detect 69% of cases of advanced adenomas. The radiological strategies would be less expensive if ACBE cost less than $115 or virtual colonoscopy cost less than $291. The colonoscopy strategy was more cost-effective if the probability of an adenoma was > or = 33.5%. When the incremental costs were considered to investigate 1000 patients, virtual colonoscopy and sigmoidoscopy with ACBE were both more costly then colonoscopy, and neither detected as many cases of advanced adenomas. CONCLUSION: Improved access to colonoscopy seems to be the preferred approach to deal with increased referrals.     

Knockout mice lacking steroidogenic factor 1 are a novel genetic model of hypothalamic obesity.

Knockout (KO) mice lacking steroidogenic factor 1 (SF-1) exhibit a phenotype that includes adrenal and gonadal agenesis, impaired gonadotropin expression, and abnormalities of the ventromedial hypothalamic nucleus (VMH). Studies in rodents with lesions of the ventromedial hypothalamus have implicated the VMH in body weight regulation, suggesting that SF-1 KO mice may provide a genetic model of obesity. To prevent death, SF-1 KO mice were rescued with corticosteroid injections, followed by syngeneic adrenal transplants from wild-type (WT) littermates. Corticosterone and ACTH levels in WT and SF-1 KO mice were indistinguishable, documenting restoration of hypothalamic-pituitary-adrenal function. Although weights at earlier ages did not differ significantly from WT littermates, SF-1 KO mice were significantly heavier by 8 wk of age and eventually weighed almost twice as much as WT controls. Obesity in SF-1 KO mice predominantly resulted from decreased activity rather than increased food intake. Leptin was increased markedly, insulin was modestly elevated, and glucose was indistinguishable from WT mice. Although sex steroids in rodents affect weight, ovariectomy did not abolish the weight difference between WT and SF-1 KO mice. These SF-1 KO mice are a genetic model of late-onset obesity that may help elucidate the role of the VMH in weight regulation.     

Hypothyroidism and heart failure

Effects of thyroid gland hormones on cardiovascular system have been known for many years. Thyroid gland hormones deficiency is connected with a range of metabolic and hemodynamic changes which can contribute to a genesis of heart failure. Recent works refer to an importance of connection of thyroid gland hormones metabolism with heart insufficiency pathophysiology. That is especially a syndrome of a low trijodthyronin level marked as euthyroid sick syndrome which is significantly more frequent in patients with chronic heart failure compared to a population of healthy individuals. Recent clinical works proved that treatment administration of thyroid gland hormones to patients with heart failure is connected with favourable hemodynamic changes and increased working capacity if the treatment is well tolerated.     

The picture of hypertrophic cardiomyopathy in the elderly

The aim of the study was to analyse the findings obtained in 27 patients with hypertrophic cardiomyopathy who lived to be 60 and more. Elderly patients are, more frequently than younger ones, women, mostly with a negative family history (81% vs. 30% in younger patients), with a lower incidence of syncope (11% vs. 25%), smaller myocardial wall thickness and lesser extent of hypertrophy. Elderly patients displayed mitral ring calcification more often (18%) than younger subjects (6%) or those of the same age but free of hypertrophic cardiomyopathy (3%). Pathological Q waves on the ECG recording were likewise less frequent (7.6% vs. 20.4%). While elderly patients exhibited manifest proneness to elevated values of left ventricular end-diastolic pressure, there were no marked differences in obstruction.