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1.
ASAIO J ; 2024 Jun 24.
Article in English | MEDLINE | ID: mdl-38905611

ABSTRACT

Right ventricular (RV) dysfunction (RVD) after orthotopic heart transplantation (OHT) is a common cause of morbidity and mortality. Impella RP Flex was recently approved for RV support as a temporary mechanical circulatory device. We present the first case of its use in managing RVD in a patient after OHT. Here, a 40 year old male patient with familial dilated cardiomyopathy and factor V Leiden mutation presented with Society for Cardiovascular Angiography & Interventions (SCAI) stage B cardiogenic shock. Hemodynamics at admission were indicative of need for intra-aortic balloon pump (IABP) support. Hemodynamics improved and patient underwent OHT. Postoperative day (POD) 1, IABP support was changed to 1:2 and eventually removed. Hemodynamics deteriorated quickly, requiring pharmacologic RV support and diuresis, but refractory RV failure persisted. Impella RP Flex was chosen due to the patient's small size and was placed via the right internal jugular vein on POD 12. The procedure was well tolerated, with the patient ambulatory the following day (POD 13). Impella was removed on POD 25 after 13 days of support. Patient achieved normal kidney, intrinsic rhythm improved sinus rhythm, and ultimately discharged on POD 50. Impella RP flex has emerged as a promising future indication as single or biventricular support postcardiac transplantation.

2.
J Heart Lung Transplant ; 43(7): 1118-1125, 2024 Jul.
Article in English | MEDLINE | ID: mdl-38373559

ABSTRACT

BACKGROUND: Endomyocardial biopsy (EMB)-based traditional microscopy remains the gold standard for the detection of cardiac allograft rejection, despite its limitation of inherent subjectivity leading to inter-reader variability. Alternative techniques now exist to surveil for allograft injury and classify rejection. Donor-derived cell-free DNA (dd-cfDNA) testing is now a validated blood-based assay used to surveil for allograft injury. The molecular microscope diagnostic system (MMDx) utilizes intragraft rejection-associated transcripts (RATs) to classify allograft rejection and identify injury. The use of dd-cfDNA and MMDx together provides objective molecular insight into allograft injury and rejection. The aim of this study was to measure the diagnostic agreement between dd-cfDNA and MMDx and assess the relationship between dd-cfDNA and MMDx-derived RATs, which may provide further insight into the pathophysiology of allograft rejection and injury. METHODS: This is a retrospective observational study of 156 EMB evaluated with traditional microscopy and MMDx. All samples were paired with dd-cfDNA from peripheral blood before EMB (up to 9 days). Diagnostic agreement between traditional histopathology, MMDx, and dd-cfDNA (threshold of 0.20%) was compared for assessment of allograft injury. In addition, the relationship between dd-cfDNA and individual RAT expression levels from MMDx was evaluated. RESULTS: MMDx characterized allograft tissue as no rejection (62.8%), antibody-mediated rejection (ABMR) (26.9%), T-cell-mediated rejection (TCMR) (5.8%), and mixed ABMR/TCMR (4.5%). For the diagnosis of any type of rejection (TCMR, ABMR, and mixed rejection), there was substantial agreement between MMDx and dd-cfDNA (76.3% agreement). All transcript clusters (group of gene sets designated by MMDx) and individual transcripts considered abnormal from MMDx had significantly elevated dd-cfDNA. In addition, a positive correlation between dd-cfDNA levels and certain MMDx-derived RATs was observed. Tissue transcript clusters were correlated with dd-cfDNA scores, including DSAST, GRIT, HT1, QCMAT, and S4. For individual transcripts, tissue ROBO4 was significantly correlated with dd-cfDNA in both nonrejection and rejection as assessed by MMDx. CONCLUSIONS: Collectively, we have shown substantial diagnostic agreement between dd-cfDNA and MMDx. Furthermore, based on the findings presented, we postulate a common pathway between the release of dd-cfDNA and expression of ROBO4 (a vascular endothelial-specific gene that stabilizes the vasculature) in the setting of antibody-mediated rejection, which may provide a mechanistic rationale for observed elevations in dd-cfDNA in AMR, compared to acute cellular rejection.


Subject(s)
Cell-Free Nucleic Acids , Graft Rejection , Heart Transplantation , Tissue Donors , Graft Rejection/diagnosis , Cell-Free Nucleic Acids/blood , Retrospective Studies , Male , Humans , Middle Aged , Female , Adult , Biopsy , Myocardium/pathology , Myocardium/metabolism
3.
J Heart Lung Transplant ; 43(3): 359-368, 2024 Mar.
Article in English | MEDLINE | ID: mdl-37730189

ABSTRACT

BACKGROUND: The purpose of the study is to investigate the relationship between blood and tissue-derived rejection-related transcripts from blood gene expression profiling (GEP) and molecular microscope in the setting of allograft rejection in heart transplant. METHODS: All heart transplant patients from August 2021 to May 2022 with both circulating blood GEP (AlloMap) and endomyocardial biopsy with molecular microscope diagnostic system (MMDx) within 4 weeks were included (N = 173 samples). We obtained individual blood GEP-based messenger RNA transcript expression levels of the 11 target genes from CareDx. Student's t-test was performed to compare blood GEP transcript expression levels between no rejection and rejection as assessed by MMDx. A Scatter plot with Spearman correlation analysis was performed to compare the relationship between transcript expression levels from AlloMap and MMDx, with and without allograft rejection. RESULTS: There were 52 samples (30.1%) with antibody-mediated rejection (ABMR) and 15 samples (8.7%) with T-cell-mediated rejection (TCMR), as assessed by MMDx. Expression of one of the blood ITGA4 (Integrin alpha 4) expression level was elevated in ABMR, compared to no ABMR (4,607.5 vs 4,217.5; p = 0.019). Most tissue rejection-associated transcript expression levels were elevated in ABMR, and tissue ROBO4 expression correlated with the blood ITGA4 expression with moderate or greater effect size in all samples (Spearman's R = 0.31; p < 0.001). There was also a positive correlation between blood ITGA4 and tissue ROBO4 expression in samples without ABMR (Spearman's R = 0.33; p < 0.001), but no correlation between blood ITGA4 and tissue ROBO4 expression in samples with ABMR (Spearman's R = 0.009; p = 0.513). CONCLUSIONS: Circulating blood ITGA4 expression is elevated in antibody-mediated rejection (AMR) and correlates with myocardial expression of ROBO4. The knowledge of individual transcript expression levels in blood and in tissue may provide insights into various disease processes in heart transplant patients. Taken together, the results of our study reveal an overlap between 2 objective post-heart transplant rejection surveillance methods, identify potential novel markers for ABMR, and reveal the need for a deeper understanding of molecular mechanisms underlying allograft rejection.


Subject(s)
Doxorubicin/analogs & derivatives , Heart Transplantation , Kidney Transplantation , Humans , Biopsy , Gene Expression Profiling , Antibodies
4.
Toxics ; 10(9)2022 Aug 29.
Article in English | MEDLINE | ID: mdl-36136476

ABSTRACT

BACKGROUND AND OBJECTIVES: Conditions such as trauma, burns, sepsis, or acute intoxications have considerable consequences on the endocrine status, causing "sick euthyroid syndrome". Organophosphate exposure may induce an increase in acetylcholine levels, thus altering the thyroid's hormonal status. The present study aims to identify the effects of acetylcholinesterase inhibition on thyroid hormones. MATERIAL AND METHODS: A prospective experimental study was conducted on twenty Wistar rats. Blood samples were drawn to set baseline values for thyroid-stimulating hormone (TSH), triiodothyronine (T3), and thyroxine (T4). Chlorpyrifos 0.1 mg/kg was administered by oral gavage to induce acetyl-cholinesterase inhibition. After exhibiting cholinergic symptoms, blood samples were collected to assess levels of cholinesterase and thyroid hormones using ELISA. RESULTS: Butyrylcholinesterase levels confirmed major inhibition immediately after intoxication compared to the baseline, certifying the intoxication. A significant increase in T4 levels was noted (p = 0.01) both at 2 h and 48 h after administration of organophosphate in sample rats. Similarly, T3 almost doubled its value 2 h after poisoning (4.2 ng/mL versus 2.5 ng/mL at baseline). Surprisingly, TSH displayed acute elevation with an afterward slow descending trend at 48 h (p = 0.1), reaching baseline value. CONCLUSIONS: This study demonstrated that cholinesterase inhibition caused major alterations in thyroid hormone levels, which may be characterized by a transient hypothyroidism status with an impact on survival prognosis.

6.
Nature ; 543(7644): 188-189, 2017 03 08.
Article in English | MEDLINE | ID: mdl-28277507
7.
J Card Fail ; 21(10): 792-7, 2015 Oct.
Article in English | MEDLINE | ID: mdl-25937146

ABSTRACT

BACKGROUND: Proven strategies to reduce right ventricular (RV) dysfunction after continuous-flow left ventricular assist device (CF-LVAD) implantation are lacking. We sought to evaluate the tolerability, feasibility, efficacy, and pharmacokinetics of inhaled milrinone (iMil) delivery after CF-LVAD implantation. METHODS AND RESULTS: We prospectively evaluated fixed-dose nebulized iMil delivered into a ventilator circuit for 24 hours in 10 postoperative CF-LVAD (Heartmate-II) patients. Tolerability (arrhythmias, hypotension, and hypersensitivity reaction), efficacy (hemodynamics), pharmacokinetics (plasma milrinone levels), and cost data were collected.Mean age was 56 ± 9 years, 90% were male, and mean INTERMACS profile was 2.5 ± 0.8. No new atrial arrhythmia events occurred, although 3 (30%) ventricular tachycardia (1 nonsustained, 2 sustained) events occurred. Sustained hypotension, drug hypersensitivity, death, or need for right ventricular assist device were not observed. Invasive mean pulmonary arterial pressure from baseline to during iMil therapy was improved (P = .017). Mean plasma milrinone levels (ng/mL) at baseline, and 1, 4, 8, 12, and 24 hours were 74.2 ± 35.4, 111.3 ± 70.9, 135.9 ± 41.5, 205.0 ± 86.7, 176.8 ± 61.3 187.6 ± 105.5, respectively. Reduced institutional cost was observed when iMil was compared with nitric oxide therapy over 24 hours ($165.29 vs $1,944.00, respectively). CONCLUSIONS: iMil delivery after CF-LVAD implantation was well tolerated, feasible, and demonstrated favorable hemodynamic, pharmacokinetic, and cost profiles. iMil therapy warrants further study in larger clinical trials.


Subject(s)
Heart Failure/drug therapy , Heart Failure/surgery , Heart-Assist Devices/trends , Milrinone/administration & dosage , Administration, Inhalation , Aged , Cost-Benefit Analysis , Female , Heart Failure/diagnosis , Heart Ventricles , Hemodynamics/drug effects , Hemodynamics/physiology , Humans , Male , Middle Aged , Milrinone/economics , Postoperative Care/economics , Postoperative Care/methods , Treatment Outcome , Vasodilator Agents/administration & dosage , Vasodilator Agents/economics , Ventricular Dysfunction, Right/prevention & control
8.
J Card Fail ; 20(5): 376.e25-32, 2014 May.
Article in English | MEDLINE | ID: mdl-25075395

ABSTRACT

BACKGROUND: Ultrafiltration (UF) is used to treat patients with diuretic-resistant acute decompensated heart failure. The aim of this study was to identify predictors and the effect of worsening renal failure(WRF) on mortality in patients treated with UF. METHODS AND RESULTS: Based on changes in serum creatinine, 99 patients treated with UF were divided into WRF and control groups. Overall creatinine increased from 1.9 ± 0.7 to 1.2 ± 1.0 mg/dL (P!.001),and WRF developed in 41% of the subjects. The peak UF rate was higher in the WRF group in univariate analysis (174 ± 75 vs 144 ± 52 mL/h; P = .03). Based on multivariate analysis, aldosterone antagonist treatment (odds ratio [OR] 3.38, 95% confidence interval [CI] 1.17-13.46, P = .04), heart rate ≤65 beats/min (OR 6.03, 95% CI 1.48-48.42; P = .03), and E/E0 ≥ 15 (OR 3.78, 95% CI 1.26-17.55; P 5 .04) at hospital admission were associated with WRF. Patients with baseline glomerular filtration rate (GFR) ≤60mg/dL who developed WRF during UF had a 75% 1-year mortality rate. CONCLUSIONS: WRF occurred frequently during UF. Increased LV filling pressures, lower heart rate, and treatment with aldosterone antagonist at hospital admission can identify patients at increased risk for WRF. Patients with baseline GFR ≤60 mg/dL and WRF during UF have an extremely high 1-year mortality rate.


Subject(s)
Heart Failure/diagnosis , Heart Failure/therapy , Hemodiafiltration/trends , Kidney/physiology , Renal Insufficiency/diagnosis , Renal Insufficiency/therapy , Acute Disease , Aged , Aged, 80 and over , Female , Heart Failure/physiopathology , Humans , Male , Middle Aged , Predictive Value of Tests , Renal Insufficiency/physiopathology , Retrospective Studies , Treatment Outcome , Ultrafiltration/trends
10.
J Card Fail ; 19(12): 787-94, 2013 Dec.
Article in English | MEDLINE | ID: mdl-24216101

ABSTRACT

BACKGROUND: Ultrafiltration (UF) is used to treat patients with diuretic-resistant acute decompensated heart failure. The aim of this study was to identify predictors and the effect of worsening renal failure (WRF) on mortality in patients treated with UF. METHODS AND RESULTS: Based on changes in serum creatinine, 99 patients treated with UF were divided into WRF and control groups. Overall creatinine increased from 1.9 ± 9.7 to 2.2 ± 2.0 mg/dL (P < .001), and WRF developed in 41% of the subjects. The peak UF rate was higher in the WRF group in univariate analysis (174 ± 45 vs 144 ± 42 mL/h; P = .03). Based on multivariate analysis, aldosterone antagonist treatment (odds ratio [OR] 3.38, 95% confidence interval [CI] 1.17-13.46, P = .04), heart rate ≤65 beats/min (OR 6.03, 95% CI 1.48-48.42; P = .03), and E/E' ≥15 (OR 3.78, 95% CI 1.26-17.55; P = .04) at hospital admission were associated with WRF. Patients with baseline glomerular filtration rate (GFR) ≤60 mg/dL who developed WRF during UF had a 75% 1-year mortality rate. CONCLUSIONS: WRF occurred frequently during UF. Increased LV filling pressures, lower heart rate, and treatment with aldosterone antagonist at hospital admission can identify patients at increased risk for WRF. Patients with baseline GFR ≤60 mg/dL and WRF during UF have an extremely high 1-year mortality rate.


Subject(s)
Heart Failure/physiopathology , Heart Failure/therapy , Hemofiltration/trends , Kidney/physiology , Renal Insufficiency/physiopathology , Renal Insufficiency/therapy , Acute Disease , Aged , Female , Heart Failure/mortality , Heart Rate/physiology , Hemofiltration/methods , Hemofiltration/mortality , Hospitalization/trends , Humans , Male , Middle Aged , Mortality/trends , Predictive Value of Tests , Renal Insufficiency/mortality , Retrospective Studies , Treatment Outcome , Ultrafiltration/methods , Ultrafiltration/trends
11.
Cardiol Rev ; 21(4): 203-6, 2013.
Article in English | MEDLINE | ID: mdl-23535527

ABSTRACT

Adenovirus infections have been associated with significant morbidity and mortality in immunocompromised hosts. The clinical significance of adenovirus disease in heart transplantation is not well-defined; in particular, the significance of adenovirus identification in myocardium remains unclear. Although severe adenovirus disease has been described in heart transplant recipients, adenovirus infections seem to be more frequently associated with increased risk of adverse cardiac events, such as rejection, ventricular dysfunction, coronary vasculopathy, need for retransplantation, and graft loss because of death. Cidofovir is currently considered the standard of treatment for adenovirus disease not responding to reduction of immunosuppression.


Subject(s)
Adenovirus Infections, Human/complications , Adenovirus Infections, Human/epidemiology , Heart Transplantation/adverse effects , Opportunistic Infections/complications , Opportunistic Infections/epidemiology , Adenovirus Infections, Human/drug therapy , Antiviral Agents/therapeutic use , Cidofovir , Coronary Disease/epidemiology , Cytosine/analogs & derivatives , Cytosine/therapeutic use , Graft Rejection/epidemiology , Humans , Incidence , Opportunistic Infections/drug therapy , Organophosphonates/therapeutic use , Risk Factors , Ventricular Dysfunction/epidemiology
12.
Molecules ; 17(9): 10355-69, 2012 Aug 29.
Article in English | MEDLINE | ID: mdl-22932216

ABSTRACT

Green tea extracts (GTEs) as well as their main component, the polyphenol epigallocatechin gallate (EGCG), are known for their versatile antioxidant, antimicrobial, antitumoral or anti-inflammatory effects. In spite of the huge beneficial action, there is increasing evidence that under certain conditions green tea and its components can be detrimental to living organisms. Using Saccharomyces cerevisiae strains with various defects in the response to oxidative stress, we found that GTEs or EGCG act in synergy with visible light, exhibiting either deleterious or protective effects depending on the solvent employed. Similar synergistic effects could be observed under singlet oxygen-generating conditions, such as light exposure in the presence of photosensitizers or UV-A irradiation, therefore solvent variance may represent a powerful tool to modulate the preparation of green tea extracts, depending on the intended target.


Subject(s)
Catechin/analogs & derivatives , Light , Saccharomyces cerevisiae/drug effects , Singlet Oxygen/metabolism , Ultraviolet Rays/adverse effects , Anti-Infective Agents/chemistry , Anti-Infective Agents/pharmacology , Anti-Inflammatory Agents/chemistry , Anti-Inflammatory Agents/pharmacology , Antioxidants/chemistry , Antioxidants/pharmacology , Catechin/chemistry , Catechin/pharmacology , Light/adverse effects , Oxidative Stress , Photosensitizing Agents/pharmacology , Reactive Oxygen Species/metabolism , Saccharomyces cerevisiae/metabolism , Solvents , Tea
13.
Transplantation ; 94(6): 646-51, 2012 Sep 27.
Article in English | MEDLINE | ID: mdl-22918216

ABSTRACT

BACKGROUND: Liver transplantation (LTx) is a life-saving treatment of end-stage liver disease. Cardiac complications including heart failure (HF) are among the leading causes of death after LTx. THE AIM: The aim is to identify clinical and echocardiographic predictors of developing HF after LTx. METHODS: Patients who underwent LTx at the University of Nebraska Medical Center (UNMC) between January 2001 and January 2009 and had echocardiographic study before and within 6 months after transplantation were identified. Patients with coronary artery disease (>70% lesion) were excluded. HF after LTx was defined by clinical signs, symptoms, radiographic evidence of pulmonary congestion, and echocardiographic evidence of left ventricular dysfunction (left ventricle ejection fraction <50%). RESULTS: Among 107 patients (presented as mean age [SD], 55 [10] years; male, 70%) who met the inclusion criteria, 26 (24%) patients developed HF after LTx. The pre-LTx left ventricle ejection fraction did not differ between the HF (69 [7]) and the control groups (69 [7] vs. 67 [6], P=0.30). However, pre-LTx elevation of early mitral inflow velocity/mitral annular velocity (P=0.02), increased left atrial volume index (P=0.05), and lower mean arterial pressure (P=0.03) were predictors of HF after LTx in multivariate analysis. Early mitral inflow velocity/mitral annular velocity greater than 10 and left atrial volume index 40 mL/m2 or more were associated with a 3.4-fold (confidence interval, 1.2-9.4; P=0.017) and 2.9-fold (confidence interval, 1.1-7.5; P=0.03) increase in risk of development of HF after LTx, respectively. CONCLUSIONS: This study suggests that elevated markers of diastolic dysfunction during pre-LTx echocardiographic evaluation are associated with an excess risk of HF and may predict post-LTx survival.


Subject(s)
Diastole , Heart Failure/etiology , Kidney Failure, Chronic/surgery , Liver Transplantation/adverse effects , Ventricular Dysfunction, Left/complications , Ventricular Function, Left , Academic Medical Centers , Aged , Arterial Pressure , Case-Control Studies , Echocardiography, Doppler , Female , Heart Atria/diagnostic imaging , Heart Atria/physiopathology , Heart Failure/diagnostic imaging , Heart Failure/mortality , Heart Failure/physiopathology , Humans , Kaplan-Meier Estimate , Kidney Failure, Chronic/complications , Kidney Failure, Chronic/mortality , Linear Models , Liver Transplantation/mortality , Male , Middle Aged , Mitral Valve/diagnostic imaging , Mitral Valve/physiopathology , Multivariate Analysis , Nebraska , Predictive Value of Tests , Risk Assessment , Risk Factors , Stroke Volume , Time Factors , Treatment Outcome , Ventricular Dysfunction, Left/diagnostic imaging , Ventricular Dysfunction, Left/mortality , Ventricular Dysfunction, Left/physiopathology
14.
J Biol Inorg Chem ; 17(6): 961-74, 2012 Aug.
Article in English | MEDLINE | ID: mdl-22714120

ABSTRACT

Superoxide dismutases (SODs) stand in the prime line of enzymatic antioxidant defense in nearly all eukaryotic cells exposed to oxygen, catalyzing the breakdown of the superoxide anionic radical to O(2) and H(2)O(2). Overproduction of superoxide correlates with numerous pathophysiological conditions, and although the native enzyme can be used as a therapeutic agent in superoxide-associated conditions, synthetic low molecular weight mimetics are preferred in terms of cost, administration mode, and bioavailability. In this study we make use of the model eukaryote Saccharomyces cerevisiae to investigate the SOD-mimetic action of a mononuclear mixed-ligand copper(II) complex, [CuCl(acac)(tmed)] (where acac is acetylacetonate anion and tmed is N,N,N',N'-tetramethylethylenediamine). Taking advantage of an easily reproducible phenotype of yeast cells which lack Cu-Zn SOD (Sod1p), we found that the compound could act either as a superoxide scavenger in the absence of native Sod1p or as a Sod1p modulator which behaved differently under various genetic backgrounds.


Subject(s)
Coordination Complexes/pharmacology , Molecular Chaperones/antagonists & inhibitors , Saccharomyces cerevisiae Proteins/antagonists & inhibitors , Saccharomyces cerevisiae/enzymology , Coordination Complexes/chemical synthesis , Coordination Complexes/chemistry , Dose-Response Relationship, Drug , Enzyme Activation/drug effects , Ligands , Molecular Chaperones/metabolism , Molecular Structure , Saccharomyces cerevisiae/cytology , Saccharomyces cerevisiae/metabolism , Saccharomyces cerevisiae Proteins/metabolism , Structure-Activity Relationship
15.
Congenit Heart Dis ; 7(4): E50-5, 2012.
Article in English | MEDLINE | ID: mdl-22176528

ABSTRACT

Patients with congenital d-transposition of the great arteries (d-TGA) undergoing palliative atrial baffle surgery in infancy often develop systemic ventricular failure in adulthood. If they undergo cardiac transplantation, they are prone to morphologic right ventricular (RV) failure secondary to severe pulmonary hypertension as a result of systemic ventricular failure. We report a case of a patient with d-TGA and biventricular ventricular failure requiring heart transplantation (HT) that developed RV failure postoperatively because of dynamic pulmonary artery (PA) obstruction at the anastomotic site of PA. Obstruction at the site of PA anastomosis due to torsion or redundancy of the donor or recipient PA is a rare but treatable cause of postoperative RV failure. In this case, rapid identification of the etiology of RV failure and implementation of corrective therapies before the development of end-organ dysfunction, resulted in complete RV recovery and normal allograft function. This case represents the first known report of dynamic PA anastomoticobstruction resulting in RV failure after HT that was corrected with pulmonary arterioplasty, and RV assist device resulting in complete recovery.


Subject(s)
Arterial Occlusive Diseases/complications , Heart Failure/etiology , Heart Transplantation/adverse effects , Heart Ventricles , Pulmonary Artery , Transposition of Great Vessels/surgery , Adult , Cardiac Surgical Procedures/methods , Humans , Male
16.
Chembiochem ; 13(1): 80-4, 2012 Jan 02.
Article in English | MEDLINE | ID: mdl-22134988

ABSTRACT

We report here the synthesis and biochemical properties of a new peptidyl activity-based probe 1 for SUMO proteases, SENPs. The activity-based probe has at its C terminus a glycine-derived fluoromethylketone moiety as a reactive group designed to target the active-site cysteine of SENPs. Based on a study of the interactions between SENPs and SUMOs, we introduced further design elements that allow the activity-based probe to selectively target SENPs at low micromolar to high nanomolar concentrations. Moreover, 1 out-competes SUMO1 from the reversible SUMO1-SENP1 complex, thus suggesting that 1 and SUMO1 share a common binding site on SENP1.


Subject(s)
Endopeptidases/chemistry , Fluorescent Dyes/chemistry , Glycine/chemistry , Ketones/chemistry , Binding Sites , Endopeptidases/biosynthesis , Endopeptidases/metabolism , Enzyme Activation , Fluorescent Dyes/chemical synthesis , Fluorescent Dyes/metabolism , Glycine/analogs & derivatives , Glycine/chemical synthesis , Glycine/metabolism , HEK293 Cells , Humans , Ketones/chemical synthesis , Ketones/metabolism , Recombinant Proteins/biosynthesis , Recombinant Proteins/chemistry , Recombinant Proteins/metabolism
17.
Appl Microbiol Biotechnol ; 94(2): 425-35, 2012 Apr.
Article in English | MEDLINE | ID: mdl-22207212

ABSTRACT

Pho84p, the protein responsible for the high-affinity uptake and transport of inorganic phosphate across the plasma membrane, is also involved in the low-affinity uptake of heavy metals in the Saccharomyces cerevisiae cells. In the present study, the effect of PHO84 overexpression upon the heavy metal accumulation by yeast cells was investigated. As PHO84 overexpression triggered the Ire1p-dependent unfolded protein response, abundant plasma membrane Pho84p could be achieved only in ire1Δ cells. Under environmental surplus, PHO84 overexpression augmented the metal accumulation by the wild type, accumulation that was exacerbated by the IRE1 deletion. The pmr1Δ cells, lacking the gene that encodes the P-type ATPase ion pump that transports Ca(2+) and Mn(2+) into the Golgi, hyperaccumulated Mn(2+) even from normal medium when overexpressing PHO84, a phenotype which is rather restricted to metal-hyperaccumulating plants.


Subject(s)
Gene Expression , Membrane Glycoproteins/metabolism , Metals, Heavy/metabolism , Protein Serine-Threonine Kinases/metabolism , Proton-Phosphate Symporters/metabolism , Saccharomyces cerevisiae Proteins/metabolism , Saccharomyces cerevisiae/physiology , Unfolded Protein Response , Saccharomyces cerevisiae/genetics , Saccharomyces cerevisiae/metabolism
19.
Can Urol Assoc J ; 4(4): E105-8, 2010 Aug.
Article in English | MEDLINE | ID: mdl-20694087

ABSTRACT

Nephrectomy with inferior vena cava (IVC) thrombectomy for advanced renal cell carcinoma (RCC) is a challenging and morbid surgical case. We describe the use of a simple endoluminal technique to occlude the suprahepatic IVC during thrombectomy. A 60-year-old male presented with a large right-sided RCC and IVC tumour thrombus. The tip of the thrombus, which was non-adherent to the caval wall, extended to the level of the hepatic veins. After complete dissection of the kidney, we obtained suprahepatic control of the IVC by a large compliant balloon, introduced through the right internal jugular vein and inflated just below the level of the diaphragm. The IVC thrombectomy was performed in a bloodless field. Mean blood pressure remained stable during IVC balloon inflation with a total occlusion time of 10 minutes. Intraprocedural completion cavogram and postoperative Doppler ultrasonography showed no residual IVC clot. Blood loss during the thrombectomy portion of the case was scant. The patient's postoperative course was uncomplicated and, at the last follow-up, he had stable metastatic disease on sunitinib therapy. For the surgical treatment of RCC with retrohepatic IVC tumour extension, transjugular balloon occlusion of the suprahepatic IVC offers an alternative to extensive hepatic mobilization to obtain suprahepatic thrombus control. Advantages over traditional surgical methods may include decreased surgical time, lower risk of liver injury and tumour embolism. We suggest this method for further evaluation.

20.
FEBS J ; 277(19): 4027-38, 2010 Oct.
Article in English | MEDLINE | ID: mdl-20735472

ABSTRACT

The Ca(2+) -dependent response to oxidative stress caused by H(2)O(2) or tert-butylhydroperoxide (tBOOH) was investigated in Saccharomyces cerevisiae cells expressing transgenic cytosolic aequorin, a Ca(2+) -dependent photoprotein. Both H(2)O(2) and tBOOH induced an immediate and short-duration cytosolic Ca(2+) increase that depended on the concentration of the stressors. Sublethal doses of H(2)O(2) induced Ca(2+) entry into the cytosol from both extracellular and vacuolar sources, whereas lethal H(2)O(2) shock mobilized predominantly the vacuolar Ca(2+). Sublethal and lethal tBOOH shocks induced mainly the influx of external Ca(2+), accompanied by a more modest vacuolar contribution. Ca(2+) transport across the plasma membrane did not necessarily involve the activity of the Cch1p/Mid1p channel, whereas the release of vacuolar Ca(2+) into the cytosol required the vacuolar channel Yvc1p. In mutants lacking the Ca(2+) transporters, H(2)O(2) or tBOOH sensitivity correlated with cytosolic Ca(2+) overload. Thus, it appears that under H(2)O(2)-induced or tBOOH-induced oxidative stress, Ca(2+) mediates the cytotoxic effect of the stressors and not the adaptation process.


Subject(s)
Calcium/metabolism , Oxidative Stress/physiology , Aequorin/genetics , Aequorin/physiology , Cytosol/drug effects , Cytosol/metabolism , DNA Primers , Hydrogen Peroxide/pharmacology , Kinetics , Mutation , Oxidative Stress/drug effects , Polymerase Chain Reaction , Recombinant Proteins/metabolism , Saccharomyces cerevisiae/drug effects , Saccharomyces cerevisiae/genetics , Saccharomyces cerevisiae/physiology , Second Messenger Systems/physiology , Vacuoles/drug effects , Vacuoles/physiology , tert-Butylhydroperoxide/pharmacology
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