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1.
Cureus ; 15(6): e40617, 2023 Jun.
Article in English | MEDLINE | ID: mdl-37476120

ABSTRACT

Three patients were referred to our hospital because of fever of unknown origin (FUO) and thrombosis or thrombophlebitis. All of them had been under immunosuppression (IS) with rituximab. Intensive diagnostics for FUO and blood cultures remained negative. Finally, the association of fever, immunosuppression, and a vascular event led to the suspicion of Candidatus Neoehrlichia mikurensis (CNM) infection. The diagnosis was confirmed by species-specific polymerase chain reaction (PCR) in the peripheral blood. Therapy with doxycycline or rifampicin led to the resolution of the disease. A liver biopsy was performed in one patient due to hepatomegaly and elevated liver enzymes demonstrating hemophagocytosis. To our knowledge, this is the first histopathological study of liver tissue in CNM infection. The evidence of hemophagocytosis raises the question of whether symptomatic CNM infection might be in part related to host inflammatory and immune responses.

2.
Res Pract Thromb Haemost ; 7(1): 100015, 2023 Jan.
Article in English | MEDLINE | ID: mdl-36970742

ABSTRACT

Background: Limited data exist on thrombophilic risk factors and clinical outcomes in the elderly with venous thromboembolism (VTE). Objectives: To describe the prevalence of laboratory thrombophilic risk factors and their association with VTE recurrence or death in a cohort of elderly people with VTE. Methods: In 240 patients aged ≥65 years with acute VTE without active cancer or an indication for extended anticoagulation, we performed laboratory thrombophilia testing 1 year after the index VTE. Recurrence or death was assessed during the 2-year follow-up. Results: A total of 78% of patients had ≥1 laboratory thrombophilic risk factor(s). Elevated levels of von Willebrand factor, homocysteine, coagulant activity of factor VIII (FVIII:C), fibrinogen, FIX:C, and low antithrombin activity were the most prevalent risk factors (43%, 30%, 15%, 14%, 13%, and 11%, respectively). Additionally, 16.2% of patients experienced VTE recurrence and 5.8% of patients died. Patients with a von Willebrand factor of >182%, FVIII:C level >200%, homocysteine level >15µmol/L, or lupus anticoagulant had a significantly higher rate of recurrence than those without these risk factors (15.0 vs. 6.1 [P = .006], 23.5 vs. 8.2 [P = .01], 17.0 vs. 6.8 [P = .006], and 89.5 vs. 9.2 [P = .02] events per 100 patient-years, respectively). Furthermore, patients with a high fibrinogen level or hyperhomocysteinemia with a homocysteine level ≥30 µmol/L had significantly higher mortality than patients with normal levels (18.5 vs. 2.8 [P = .049] and 13.6 vs. 2 [P = .002] deaths per 100 patient-years, respectively). After adjustments for relevant confounders, these associations remained unchanged. Conclusion: Laboratory thrombophilic risk factors are common in elderly people with VTE and allow for the identification of a population at the risk of worse clinical outcomes.

4.
Thromb Haemost ; 121(5): 641-649, 2021 May.
Article in English | MEDLINE | ID: mdl-33202448

ABSTRACT

OBJECTIVE: In patients with cancer-associated venous thromboembolism (VTE), the risk of recurrence is similar after incidental and symptomatic events. It is unknown whether the same applies to incidental VTE not associated with cancer. METHODS AND RESULTS: We compared baseline characteristics, anticoagulation therapy, all-cause mortality, and VTE recurrence rates at 90 days between patients with incidental (n = 131; 52% without cancer) and symptomatic (n = 1,931) VTE included in the SWIss Venous ThromboEmbolism Registry (SWIVTER). After incidental VTE, 114 (87%) patients received anticoagulation therapy for at least 3 months. The mortality rate was 9.2% after incidental and 8.4% after symptomatic VTE for hazard ratio (HR) 1.10 (95% confidence interval [CI] 0.49-2.50). After adjustment for competing risk of death, recurrence rate was 3.1 versus 2.8%, respectively, for sub-HR 1.07 (95% CI 0.39-2.93). These results were consistent among cancer (mortality: 15.9% vs. 12.6%; HR 1.32, 95% CI 0.67-2.59; recurrence: 4.8% vs. 4.7%; HR 1.02, 95% CI 0.30-3.42) and noncancer patients (mortality: 2.9% vs. 2.1%; HR 1.37, 95% CI 0.33-5.73; recurrence: 1.5% vs. 2.3%; HR 0.63, 95% CI 0.09-4.58). Patients with incidental VTE who received anticoagulation therapy for at least 3 months had lower mortality (4% vs. 41%) and recurrence rate (1% vs. 18%) compared with those who did not. CONCLUSION: In SWIVTER, more than half of incidental VTE events occurred in noncancer patients who often received anticoagulation therapy. Among noncancer patients, early mortality and recurrence rates were similar after incidental versus symptomatic VTE. Our findings suggest that anticoagulation therapy for incidental VTE may be beneficial regardless of the presence of cancer.


Subject(s)
Anticoagulants/therapeutic use , Neoplasms/epidemiology , Registries , Venous Thromboembolism/epidemiology , Adolescent , Adult , Aged , Female , Humans , Incidence , Male , Middle Aged , Recurrence , Survival Analysis , Switzerland/epidemiology , Treatment Outcome , Venous Thromboembolism/drug therapy , Venous Thromboembolism/mortality , Young Adult
5.
Swiss Med Wkly ; 150: w20293, 2020 05 18.
Article in English | MEDLINE | ID: mdl-32459857

ABSTRACT

The emergence of severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) as a global phenomenon has presented clinicians around the world with multiple challenges. Thromboembolic events are recognised complications of viral infection, but the diagnosis of an acute pulmonary thrombotic complication in the context of coronavirus disease 2019 (COVID-19) can be challenging because of the similarities of presentation, logistical considerations of diagnosis in a patient isolated for infection control reasons and the effects of cognitive errors in diagnostic reasoning. We present the case of a patient who was diagnosed with a pulmonary thrombotic complication during inpatient care for COVID-19. The haemostasis parameters we observed, including increased levels of von Willebrand factor and factor VIII, point towards a relevant involvement of endothelial cells in patients with severe COVID-19. We suggest that it is possible to hypothesise a spectrum of secondarily acquired, prothrombotic coagulopathy mediated by the endothelial interaction with SARS-CoV-2 as a cause of mortality in a subset of patients with a complicated clinical course of COVID-19. We support the recommendation of thromboembolic chemoprophylaxis for inpatients with COVID-19 as a very minimum in the absence of strict contraindications, while recognising that pulmonary thrombotic complications can occur under standard thromboprophylaxis. We suggest that higher, possibly therapeutic levels of anticoagulation might be mandatory for a further subset of patients with COVID-19 where a discrepant evolution of C-reactive protein and D-dimer is observed. Therapeutic levels of anticoagulation are obligatory where new evidence of a macrovascular thrombotic complication has been documented. More research to delineate the macro- and microvascular thrombotic complications of COVID-19, and the therapeutic implications for this patient group is required.


Subject(s)
Betacoronavirus , Coronavirus Infections/blood , Fibrin Fibrinogen Degradation Products/metabolism , Pneumonia, Viral/blood , Pulmonary Embolism/virology , COVID-19 , Coronavirus Infections/complications , Coronavirus Infections/mortality , Coronavirus Infections/physiopathology , Humans , Male , Middle Aged , Pandemics , Pneumonia, Viral/complications , Pneumonia, Viral/mortality , Pneumonia, Viral/physiopathology , Pulmonary Embolism/mortality , Pulmonary Embolism/physiopathology , Pulmonary Embolism/therapy , SARS-CoV-2
7.
J Bone Jt Infect ; 6(3): 51-55, 2020.
Article in English | MEDLINE | ID: mdl-33552878

ABSTRACT

We report on a patient with septic arthritis of the knee with Pantoea agglomerans after a penetrating black locust thorn injury. Antibiotics alone or in combination with an arthroscopy may be insufficient for achieving source control. Accurate medical history and open debridement with a search for a thorn fragment are key to successful treatment.

8.
Semin Thromb Hemost ; 45(8): 851-858, 2019 Nov.
Article in English | MEDLINE | ID: mdl-31622993

ABSTRACT

Renal impairment (RI) has increased substantially over the last decades. In the absence of data from confirmatory research, real-life data on anticoagulation treatment and clinical outcomes of venous thromboembolism (VTE) in patients with RI are needed. In the SWIss Venous ThromboEmbolism Registry (SWIVTER), 2,062 consecutive patients with objectively confirmed VTE were enrolled. In the present analysis, we compared characteristics, initial and maintenance anticoagulation, and adjusted 90-day clinical outcomes of those with (defined as estimated creatinine clearance < 30 mL/min) and without severe RI. Overall, 240 (12%) patients had severe RI; they were older, and more frequently had chronic and acute comorbidities. VTE severity was similar between patients with and without severe RI. Initial anticoagulation in patients with severe RI was more often performed with unfractionated heparin (44 vs. 24%), and less often with low-molecular-weight heparin (LMWH) (52 vs. 61%) and direct oral anticoagulants (DOACs; 4 vs. 12%). Maintenance anticoagulation in patients with severe RI was more frequently managed with vitamin K antagonists (70 vs. 60%) and less frequently with DOAC (12 vs. 21%). Severe RI was associated with increased risk of 90-day mortality (9.2 vs. 4.2%, hazard ratio [HR]: 2.27, 95% confidence interval [CI]: 1.41-3.65), but with similar risk of recurrent VTE (3.3 vs. 2.8%, HR: 1.19, 95% CI: 0.57-2.52) and major bleeding (2.1 vs. 2.0%, HR: 1.05, 95% CI: 0.41-2.68). In patients with severe RI, the use of LMWH versus any other treatment was associated with reduced mortality (HR: 0.37; 95% CI: 0.14-0.94; p = 0.036) and similar rate of major bleeding (HR: 0.59, 95% CI: 0.17-2.00; p = 0.39). Acute or chronic comorbidities rather than VTE severity or recurrence may explain increased early mortality in patients with severe RI. The higher rate of VTE recurrence, specifically fatal events, than major bleeding reinforces the need for effective anticoagulation in VTE patients with severe RI.


Subject(s)
Renal Insufficiency, Chronic/etiology , Venous Thromboembolism/complications , Female , Humans , Male , Middle Aged , Registries , Renal Insufficiency, Chronic/pathology
9.
BMC Pediatr ; 19(1): 183, 2019 06 06.
Article in English | MEDLINE | ID: mdl-31170948

ABSTRACT

BACKGROUND: Neonatal renal vein thrombosis is a recognised cause of renal and inferior caval vein atresia (IVCA). However, the long-term impact of the condition is underrecognized with a high burden of morbidity for the patient, especially in adulthood. IVCA has been shown to be an independent risk factor for deep venous thrombosis (DVT) with a high risk of recurrence. The acronym KILT for kidney and inferior vena cava anomaly with leg thrombosis summarizes the pathological situation. CASE PRESENTATION: We present the case of a 40-year-old patient with pain in the right lower limb resulting from acute thrombophlebitis. No risk factors could be identified. His history was remarkable with two episodes of deep venous thrombosis first of the left, then the right leg 22 years earlier; at that time also, no risk factor was identified. Because of the idiopathic character of that thrombosis, the patient remained on long-term anticoagulation with phenprocoumon. The present thrombophlebitis occurred while the INR was not therapeutic in the preceding weeks. A CT with contrast showed atresia of the inferior vena cava and of the right kidney, and presence of numerous collaterals. A thorough medical history revealed a renal vein thrombosis as a neonate. Anticoagulation was intensified, and stent placement became necessary after a further 2 years. DISCUSSION AND CONCLUSIONS: KILT syndrome is a rare but underrecognized condition. Complications may arise in young adulthood only, and it is of prime importance to instruct parents of the pediatric patient of the possible consequences of renal vein thrombosis and to assure guidance from the treating physicians throughout adulthood. Diagnosis of IVCA is by CT with contrast or by MRI, and lifelong anticoagulation may be necessary. Since the KILT syndrome is widely underdiagnosed, we challenge the clinicians to keep it in mind when confronted with thrombophlebitis or thrombosis of the young, male and with no other identifiable risk factors for deep vein thrombosis.


Subject(s)
Kidney/abnormalities , Leg/blood supply , Renal Veins , Thrombophlebitis/complications , Vena Cava, Inferior/abnormalities , Venous Thrombosis/complications , Abbreviations as Topic , Adult , Anticoagulants/therapeutic use , Follow-Up Studies , Humans , Infant, Newborn , Male , Pain/etiology , Phenprocoumon/therapeutic use , Renal Veins/diagnostic imaging , Syndrome , Time Factors , Tomography, X-Ray Computed , Vascular Malformations/diagnostic imaging , Vascular Malformations/etiology , Vena Cava, Inferior/diagnostic imaging , Venous Thrombosis/drug therapy
10.
BMJ Open ; 8(6): e022943, 2018 06 09.
Article in English | MEDLINE | ID: mdl-29886450

ABSTRACT

OBJECTIVES: To investigate the accuracy, reproducibility and costs of different laboratory assays for the monitoring of unfractionated heparin (UFH) in clinical practice and to study test utilisation in Switzerland. DESIGN: Prospective evaluation study and survey among Swiss hospitals and laboratories. SETTING: Secondary care hospital in rural Switzerland (evaluation study); all Swiss hospitals and laboratories (survey). PARTICIPANTS: All consecutive patients, monitored for treatment with UFH during two time periods, were included (May to July 2014 and January to February 2015; n=254). OUTCOME MEASURES: Results of activated partial thromboplastin time (aPTT), thrombin time (TT), prothrombinase-induced clotting time (PiCT) and anti-Xa activity with respect to UFH concentration RESULTS: Spearman's correlation coefficient (rs) with regard to anti-Xa activity was 0.68 (95% CI 0.60 to 0.75) for aPTT, 0.79 (0.69 to 0.86) for TT and 0.94 (0.93 to 0.95) for PiCT. The correlation (rs) between anti-Xa activity and heparin concentration as determined by spiking plasma samples was 1.0 (1.0 to 1.0). The coefficient of variation was at most 5% for PiCT and anti-Xa activity (within-run as well as day-to-day variability). The total costs per test in Swiss Francs (SFr) were SFr23.40 for aPTT, SFr33.30 for TT, SFr15.70 for PiCT and SFr24.15 for anti-Xa activity. The various tests were employed in Swiss institutions with the following frequencies: aPTT 53.2%, TT 21.6%, anti-Xa activity 7.2%, PiCT 1.4%; 16.6% of hospitals performed more than one test. CONCLUSIONS: The accuracy and reproducibility of PiCT and anti-Xa activity for monitoring of UFH was superior, and analytical costs were equivalent to or lower than aPTT and TT.


Subject(s)
Blood Coagulation Tests/economics , Blood Coagulation Tests/standards , Drug Monitoring/methods , Heparin/blood , Costs and Cost Analysis , Humans , Linear Models , Prospective Studies , Reproducibility of Results , Surveys and Questionnaires , Switzerland , Time Factors
14.
Thromb Haemost ; 116(3): 472-9, 2016 08 30.
Article in English | MEDLINE | ID: mdl-27346301

ABSTRACT

We investigated three-month clinical outcomes in patients with venous thromboembolism (VTE) treated with rivaroxaban or conventional anticoagulation in routine clinical practice. Between November 2012 and February 2015, 2,062 consecutive patients with VTE from 11 acute care hospitals in Switzerland were enrolled in the SWIss Venous ThromboEmbolism Registry (SWIVTER). Overall, 417 (20 %) patients were treated with rivaroxaban. In comparison to 1,645 patients on conventional anticoagulation, patients on rivaroxaban were younger (56 ± 18 vs. 65 ± 17 years; p<0.001), less often had pulmonary embolism (38 % vs 66 %; p<0.001), hypertension (26 % vs 41 %; p<0.001), cancer (10 % vs 28 %; p<0.001), congestive heart failure (10 % vs 17 %; p=0.001), diabetes (8 % vs 15 %; p<0.001), chronic lung disease (7 % vs 13 %; p=0.001), renal insufficiency (7 % vs 13 %; p=0.001), recent surgery (7 % vs 14 %; p<0.001), and acute coronary syndrome (1 % vs 4 %; p=0.009). VTE reperfusion therapy was more frequently used (28 % vs 9 %; p<0.001) and indefinite-duration anticoagulation treatment less often planned (26 % vs 39 %; p<0.001), respectively. In the propensity score-adjusted population, the risk of recurrent VTE was similar in patients on rivaroxaban vs conventional anticoagulation (1.2 % vs 2.1 %, hazard ratio [HR] 0.55, 95 % confidence interval [CI] 0.18-1.65; p=0.29); the risk of major bleeding was also similar, respectively (0.5 % vs 0.5 %, HR 1.00, 95 %CI 0.14-7.07; p=1.00). Conventional anticoagulation is still frequently used for the treatment of VTE, particularly in the elderly and those with comorbidities. Early clinical outcomes were comparable between propensity score-adjusted patient populations on rivaroxaban and conventional anticoagulation.


Subject(s)
Factor Xa Inhibitors/therapeutic use , Rivaroxaban/therapeutic use , Venous Thromboembolism/drug therapy , Adult , Aged , Aged, 80 and over , Anticoagulants/adverse effects , Anticoagulants/therapeutic use , Factor Xa Inhibitors/adverse effects , Female , Hemorrhage/chemically induced , Humans , Male , Middle Aged , Pulmonary Embolism/drug therapy , Registries , Retrospective Studies , Rivaroxaban/adverse effects , Switzerland , Thrombolytic Therapy , Treatment Outcome
15.
Semin Thromb Hemost ; 42(6): 642-9, 2016 Sep.
Article in English | MEDLINE | ID: mdl-27272967

ABSTRACT

Background The association between cancer and venous thromboembolism (VTE) in producing adverse clinical outcomes requires further investigation. Methods In the Swiss Venous ThromboEmbolism Registry (SWIVTER), we compared adverse clinical outcomes between 493 patients with cancer-associated VTE and 1,569 VTE patients without cancer, and identified independent predictors of 90-day mortality. Results Among cancer patients, 351 (71%) had active disease at the time of VTE diagnosis and 232 (47%) had metastatic disease. Cancer patients more frequently had asymptomatic VTE (13 vs. 4%; p < 0.001), iliofemoral deep vein thrombosis (42 vs. 32%; p = 0.017), and upper extremity deep vein thrombosis (16 vs. 7%; p < 0.001). Cancer was associated with an increased risk of cumulative 90-day mortality (13.0 vs. 2.2%; hazard ratio [HR], 6.27; 95% confidence interval [CI], 4.13-9.50; p < 0.001), recurrent VTE (4.7 vs. 2.3%; HR, 2.05; 95% CI, 1.21-3.45; p = 0.007), and bleeding requiring medical attention (5.7 vs. 3.3%; HR, 1.80; 95% CI, 1.13-2.86; p = 0.013). Among cancer patients, the strongest factor associated with mortality was metastatic disease (HR, 4.86; 95% CI, 2.68-8.81; p < 0.001), whereas it was pulmonary embolism among noncancer patients (HR, 4.96; 95% CI, 1.50-16.45; p = 0.009). Symptomatic as compared with asymptomatic VTE predicted neither mortality (12.6 vs. 15.9%; HR, 0.76; 95% CI, 0.39-1.49; p = 0.42) nor recurrent VTE (4.7 vs. 4.8%; HR, 0.98; 95% CI, 0.29-3.31; p = 0.98) in cancer patients. Conclusion In SWIVTER, early mortality of cancer-associated VTE was mainly driven by the extent of cancer disease and not by VTE symptoms or severity.


Subject(s)
Neoplasms , Registries , Venous Thromboembolism , Adult , Aged , Aged, 80 and over , Female , Humans , Male , Middle Aged , Neoplasms/classification , Neoplasms/diagnosis , Neoplasms/mortality , Switzerland/epidemiology , Venous Thromboembolism/diagnosis , Venous Thromboembolism/etiology , Venous Thromboembolism/mortality
16.
BMC Infect Dis ; 16: 198, 2016 May 14.
Article in English | MEDLINE | ID: mdl-27177684

ABSTRACT

BACKGROUND: Campylobacter fetus subspecies fetus (CFF) is an important pathogen for both cattle and humans. We performed a systematic epidemiological and clinical study of patients and evaluated the genetic relatedness of 17 human and 17 bovine CFF isolates by using different genotyping methods. In addition, the serotype, the dissemination of the genomic island containing a type IV secretion system (T4SS) and resistance determinants for tetracycline and streptomycin were also evaluated. METHODS: The isolates from patients diagnosed with CFF infection as well as those from faecal samples of healthy calves were genotyped using pulsed-field gel electrophoresis (PFGE), multilocus sequence typing (MLST), as well as single locus sequence typing (SLST) targeting cmp1 and cmp2 genes encoding two major outer membrane proteins in CFF. The presence of the genomic island and identification of serotype was determined by PCRs targeting genes of the T4SS and the sap locus, respectively. Tetracycline and streptomycin resistance phenotypes were determined by minimal inhibitory concentration. Clinical data obtained from medical records and laboratory data were supplemented by data obtained via telephone interviews with the patients and treating physicians. RESULTS: PFGE analysis defined two major clusters; cluster A containing 16 bovine (80 %) isolates and cluster B containing 13 human (92 %) isolates, suggesting a host preference. Further genotypic analysis using MLST, SLST as well as sap and T4SS PCR showed the presence of genotypically identical isolates in cattle and humans. The low diversity observed within the cmp alleles of CFF corroborates the clonal nature of this pathogen. The genomic island containing the tetracycline and streptomycin resistance determinants was found in 55 % of the isolates in cluster A and correlated with phenotypic antibiotic resistance. CONCLUSIONS: Most human and bovine isolates were separated on two phylogenetic clusters. However, several human and bovine isolates were identical by diverse genotyping methods, indicating a possible link between strains from these two hosts.


Subject(s)
Campylobacter Infections/epidemiology , Campylobacter fetus/drug effects , Campylobacter fetus/genetics , Drug Resistance, Bacterial/genetics , Adult , Aged , Aged, 80 and over , Animals , Anti-Bacterial Agents/pharmacology , Campylobacter Infections/drug therapy , Campylobacter Infections/microbiology , Campylobacter Infections/veterinary , Campylobacter fetus/pathogenicity , Cattle , Drug Resistance, Bacterial/drug effects , Electrophoresis, Gel, Pulsed-Field , Female , Genotype , Humans , Male , Microbial Sensitivity Tests , Middle Aged , Multilocus Sequence Typing , Phenotype , Phylogeny , Polymerase Chain Reaction , Streptomycin/pharmacology , Switzerland/epidemiology , Tetracycline/pharmacology
17.
J Endocrinol ; 219(2): 119-29, 2013 Nov.
Article in English | MEDLINE | ID: mdl-24096962

ABSTRACT

The intracellular availability of glucocorticoids is regulated by the enzymes 11ß-hydroxysteroid dehydrogenase 1 (HSD11B1) and 11ß-hydroxysteroid dehydrogenase 2 (HSD11B2). The activity of HSD11B1 is measured in the urine based on the (tetrahydrocortisol+5α-tetrahydrocortisol)/tetrahydrocortisone ((THF+5α-THF)/THE) ratio in humans and the (tetrahydrocorticosterone+5α-tetrahydrocorticosterone)/tetrahydrodehydrocorticosterone ((THB+5α-THB)/THA) ratio in mice. The cortisol/cortisone (F/E) ratio in humans and the corticosterone/11-dehydrocorticosterone (B/A) ratio in mice are markers of the activity of HSD11B2. In vitro agonist treatment of liver X receptor (LXR) down-regulates the activity of HSD11B1. Sterol 27-hydroxylase (CYP27A1) catalyses the first step in the alternative pathway of bile acid synthesis by hydroxylating cholesterol to 27-hydroxycholesterol (27-OHC). Since 27-OHC is a natural ligand for LXR, we hypothesised that CYP27A1 deficiency may up-regulate the activity of HSD11B1. In a patient with cerebrotendinous xanthomatosis carrying a loss-of-function mutation in CYP27A1, the plasma concentrations of 27-OHC were dramatically reduced (3.8 vs 90-140 ng/ml in healthy controls) and the urinary ratios of (THF+5α-THF)/THE and F/E were increased, demonstrating enhanced HSD11B1 and diminished HSD11B2 activities. Similarly, in Cyp27a1 knockout (KO) mice, the plasma concentrations of 27-OHC were undetectable (<1 vs 25-120 ng/ml in Cyp27a1 WT mice). The urinary ratio of (THB+5α-THB)/THA was fourfold and that of B/A was twofold higher in KO mice than in their WT littermates. The (THB+5α-THB)/THA ratio was also significantly increased in the plasma, liver and kidney of KO mice. In the liver of these mice, the increase in the concentrations of active glucocorticoids was due to increased liver weight as a consequence of Cyp27a1 deficiency. In vitro, 27-OHC acts as an inhibitor of the activity of HSD11B1. Our studies suggest that the expression of CYP27A1 modulates the concentrations of active glucocorticoids in both humans and mice and in vitro.


Subject(s)
Cholestanetriol 26-Monooxygenase/physiology , Glucocorticoids/metabolism , Homeostasis/physiology , Xanthomatosis, Cerebrotendinous/metabolism , 11-beta-Hydroxysteroid Dehydrogenase Type 1/metabolism , Animals , Cholestanetriol 26-Monooxygenase/genetics , Cholestanetriol 26-Monooxygenase/metabolism , Disease Models, Animal , Female , Humans , In Vitro Techniques , Male , Mice , Mice, Inbred C57BL , Mice, Knockout , Mutation/genetics , Xanthomatosis, Cerebrotendinous/genetics , Xanthomatosis, Cerebrotendinous/physiopathology
19.
Arterioscler Thromb Vasc Biol ; 31(12): 2836-44, 2011 Dec.
Article in English | MEDLINE | ID: mdl-21921259

ABSTRACT

OBJECTIVE: The concept of vascular pruning, the "cuting-off" of vessels, is gaining importance due to expansion of angio-modulating therapies. The proangiogenic effects of vascular endothelial growth factor (VEGF) are broadly described, but the mechanisms of structural alterations by its downregulation are not known. METHODS AND RESULTS: VEGF(165)-releasing hydrogels were applied onto the chick chorioallantoic membrane on embryonic day 10. The hydrogels, designed to completely degrade within 2 days, caused high-level VEGF presentation followed by abrupt VEGF withdrawal. Application of VEGF resulted in a pronounced angiogenic response within 24 hours. The drastic decrease in level of exogenous VEGF-A within 48 hours was corroborated by enzyme-linked immunosorbent assay. Following this VEGF withdrawal we observed vasculature adaptation by means of intussusception, including intussusceptive vascular pruning. As revealed on vascular casts and serial semithin sections, intussusceptive vascular pruning occurred by emergence of multiple eccentric pillars at bifurcations. Time-lapse in vivo microscopy has confirmed the de novo occurrence of transluminal pillars and their capability to induce pruning. Quantitative evaluation corroborated an extensive activation of intussusception associated with VEGF withdrawal. CONCLUSIONS: Diminution of VEGF level induces vascular tree regression by intussusceptive vascular pruning. This observation may allude to the mechanism underlying the "normalization" of tumor vasculature if treated with antiangiogenic drugs. The mechanism described here gives new insights into the understanding of the processes of vasculature regression and hence provides new and potentially viable targets for antiangiogenic and/or angio-modulating therapies during various pathological processes.


Subject(s)
Chorioallantoic Membrane/blood supply , Neovascularization, Physiologic/physiology , Signal Transduction/physiology , Vascular Endothelial Growth Factor A/deficiency , Animals , Apoptosis/physiology , Chick Embryo , Endothelium, Vascular/pathology , Endothelium, Vascular/physiology , Gene Expression Regulation/physiology , Models, Animal , Neovascularization, Physiologic/drug effects , Neovascularization, Physiologic/genetics , Signal Transduction/genetics , Time Factors , Vascular Endothelial Growth Factor A/genetics , Vascular Endothelial Growth Factor A/pharmacology
20.
Nat Genet ; 43(10): 1012-7, 2011 Sep 04.
Article in English | MEDLINE | ID: mdl-21892162

ABSTRACT

We report the discovery of GATA2 as a new myelodysplastic syndrome (MDS)-acute myeloid leukemia (AML) predisposition gene. We found the same, previously unidentified heterozygous c.1061C>T (p.Thr354Met) missense mutation in the GATA2 transcription factor gene segregating with the multigenerational transmission of MDS-AML in three families and a GATA2 c.1063_1065delACA (p.Thr355del) mutation at an adjacent codon in a fourth MDS family. The resulting alterations reside within the second zinc finger of GATA2, which mediates DNA-binding and protein-protein interactions. We show differential effects of the mutations on the transactivation of target genes, cellular differentiation, apoptosis and global gene expression. Identification of such predisposing genes to familial forms of MDS and AML is critical for more effective diagnosis and prognosis, counseling, selection of related bone marrow transplant donors and development of therapies.


Subject(s)
GATA2 Transcription Factor/genetics , Leukemia, Myeloid, Acute/genetics , Mutation , Myelodysplastic Syndromes/genetics , Quantitative Trait, Heritable , Amino Acid Sequence , Animals , COS Cells , Cell Differentiation , Cell Proliferation , Chlorocebus aethiops , Chromosome Mapping , DNA, Complementary , Female , GATA2 Transcription Factor/metabolism , Genetic Predisposition to Disease , HEK293 Cells , Haplotypes , Humans , Male , Molecular Sequence Data , Pedigree , Plasmids , Polymorphism, Single Nucleotide
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