Deglutarylation of glutaryl-CoA dehydrogenase by deacylating enzyme SIRT5 promotes lysine oxidation in mice.

A wide range of protein acyl modifications has been identified on enzymes across various metabolic processes; however, the impact of these modifications remains poorly understood. Protein glutarylation is a recently identified modification that can be nonenzymatically driven by glutaryl-CoA. In mammalian systems, this unique metabolite is only produced in the lysine and tryptophan oxidative pathways. To better understand the biology of protein glutarylation, we studied the relationship between enzymes within the lysine/tryptophan catabolic pathways, protein glutarylation, and regulation by the deglutarylating enzyme sirtuin 5 (SIRT5). Here, we identify glutarylation on the lysine oxidation pathway enzyme glutaryl-CoA dehydrogenase (GCDH) and show increased GCDH glutarylation when glutaryl-CoA production is stimulated by lysine catabolism. Our data reveal that glutarylation of GCDH impacts its function, ultimately decreasing lysine oxidation. We also demonstrate the ability of SIRT5 to deglutarylate GCDH, restoring its enzymatic activity. Finally, metabolomic and bioinformatic analyses indicate an expanded role for SIRT5 in regulating amino acid metabolism. Together, these data support a feedback loop model within the lysine/tryptophan oxidation pathway in which glutaryl-CoA is produced, in turn inhibiting GCDH function via glutaryl modification of GCDH lysine residues and can be relieved by SIRT5 deacylation activity.

Fabrication and development of a thorax phantom to evaluate 3D CRT treatment planning techniques for post-mastectomy chest wall radiotherapy.

The aim of this study was to design and fabricate a thorax phantom to quantify the radiation doses to the region of the chest wall (with 3 ionization chambers), the organ at risk (OAR) (lung), and the surface using radiochromic films (EBT3) for three different 3D CRT treatment planning techniques. Anthropomorphic phantoms are one of the best tools for verifying the quality of the radiotherapy treatment plans generated by treatment planning systems since they can provide equivalent human tissue densities. Thirty acrylic plates were cut into ellipses 21 cm in height and 31 cm in width, and slots were created to insert lung equivalent cork material and bone equivalent Teflon material. Three treatment planning techniques were designed: (A) tangential pair beams, (B) tangential pair beams with wedges and (C) tangential beams followed by an anterior oblique beam. The percentage difference between the measured point doses and the calculated doses (measured with three CC13 ionization chambers) ranged from - 3.2 to 1.6%, with a mean deviation of - 1.04 ± 1.3%. The measured mean percentage doses on the target surface with EBT3 film were 90.3% and 95.1% of the prescribed dose with 5-mm and 10-mm boluses, respectively. Finally, the average absolute dose difference between the measured and calculated surface doses was within 10 cGy in all three planning techniques. The developed thorax phantom is suitable for point dose measurements using ionization chambers and for surface dose measurements using EBT3 Gafchromic films in post-mastectomy chest wall radiotherapy.

Effect of domperidone, ondansetron, olanzapine-containing antiemetic regimen on QTC interval in patients with malignancy: a prospective, observational, single-group, assessor-blinded study.

Domperidone, ondansetron and olanzapine can prolong the QT interval. The clinical use of combinations of these drugs is not uncommon. Our study aimed to determine the presence of any QTc prolonging effect of the combination when used as antiemetic in patients receiving cancer chemotherapy. We carried out a prospective, observational study of patients with malignancy who were to receive domperidone, ondansetron and olanzapine-containing antiemetic regimen. Electrocardiograms were recorded before and during the administration of antiemetics, for three consecutive days. A blinded assessor determined the QTc interval using Bazett and Fridericia formulae. Thirty-six patients completed the study; 23 (63.9%) were females. There was a statistically significant change in QTc with time (Fridericia, χ2(4) = 15.629, p = 0.004; Bazett, χ2(4) = 15.910, p = 0.003); QTc on Day 1 was more than that during baseline (p < 0.001); these differences were significant in females (Fridericia, χ2(4) = 13.753, p = 0.008; Bazett, χ2 (4) = 13.278, p = 0.010) but not in males (Fridericia, χ2 (4) = 4.419, p = 0.352; Bazett, χ2(4) = 4.280, p = 0.369). Two female patients had an absolute QTc prolongation (Bazett correction) of > 500 ms. However, no clinically significant adverse events occurred. The findings show that QTc prolongation is a concern with olanzapine alone and in combination with domperidone and ondansetron, and needs to be investigated further.

Simultaneous Measurement of In vivo and Transit Mid-Plane Doses with Ionization Chambers in Gynecological Malignancy Patients Undergoing Three-Dimensional Conformal Radiotherapy.

PURPOSE: The aim of this study is to estimate delivered radiation doses inside planning tumor volume (PTV) using the in vivo (mid-plane dose) measurement and transit measurement methods in gynecological malignancy patients undergoing three-dimensional conformal radiotherapy (3DCRT) using calibrated ionization chambers. MATERIALS AND METHODS: Six patients with histopathologically proven carcinoma of the cervix or endometrium were planned with four-field 3DCRT to the pelvic site. Isocenter was at the geometric mid-plane of PTV with a dose prescription of 50 Gy in 25 fractions. Clinical mid-plane dose (D iso, Transit) estimates were done in one method (transit) using the FC-65 positioned at electronic portal imaging device level. In another method, a repeat computerized tomography scan was performed (at the 11th fraction) using CC-13 having a protective cap in the vaginal cavity for in vivo measurements (D in vivo ). Simultaneous measurements were performed with the two chambers from the 11th fraction onward at least 3-4 times during the remaining course of treatment. RESULTS: The agreement of mean doses from these two described methods and treatment planning system reference doses was in the range of -4.4 ± 1.1% (minimum) to -0.3 ± 2.0% (maximum) and -4.0 ± 1.7% (minimum) to 1.9 ± 2.4% for D in vivo and D iso, Transit , respectively, which are an acceptable range of daily radiation dose delivery. CONCLUSION: The fundamental importance of this study lies in simultaneous validation of delivered dose in real time with two methods. A study in this small number of patients has given the confidence to apply transit measurements for quality assurance on a routine basis as an accepted clinical dosimetry for the selected patients.

Curcumin as a permeability enhancer enhanced the antihyperlipidemic activity of dietary green tea extract.

BACKGROUND: Green tea has polyphenols like flavonoids and catechins; mainly epigallocatechin-3-gallate (EGCG), epicatechin gallate (ECG), epigallocatechin (EGC) and epicatechin (EC), out of which EGCG is of higher abundance. EGCG has shown preventive role in hypercholesterolemia. However, due to low oral bioavailability, a need arises to improve its membrane permeability and transporter-mediated intestinal efflux. Therefore, an attempt was made to enhance permeability and bioavailability of EGCG using curcumin to treat hyperlipidemia. Further, it was formulated in herbal tea bags to achieve patient compliance. METHODS: EGCG extracted from green tea leaves was confirmed by High Performance Thin Layer Chromatography. Green tea extract (GTE), curcumin and their mixtures were subjected to Fourier Transform Infra-Red spectroscopy and Differential Scanning Calorimetry for compatibility studies. Powder formulation was prepared comprising GTE, curcumin, sucralose and cardamom. RESULTS: Ex-vivo study was performed on everted goat intestine, analyzed by HPLC and demonstrated highest permeation of GTE:curcumin (220:50) (53.15%) than GTE (20.57%). Antihyperlipidemic activity was performed in rats for 15 days. Blood sample analysis of rats of test groups (formulation and GTE solution) fed on high fat diet showed (mg/dl):cholesterol 80 and 90, triglycerides 73.25 and 85.5, HDL 50.75 and 46, LDL 43.9 and 46, VLDL 14.65 and 17.1 respectively with significant lipid regulating effect. CONCLUSION: Curcumin enhanced permeability of EGCG. Therefore, P-glycoprotein pump inside intestine can be potential mechanism to enhance permeability of EGCG. Thus, EGCG-curcumin herbal tea bag is promising nutraceutical to treat hyperlipidemia in day-to-day life achieving patient compliance.

Accessory Splenic Artery: A Rare Cause of Upper Gastrointestinal Bleeding.

Variations in the origin and branching pattern of splenic artery are relatively common and asymptomatic, but the presence of an accessory splenic artery, that too symptomatic, is quite rare. This report describes a 67-year-old male, with no history of liver disease, who presented with recurrent upper gastrointestinal bleeding and was found to have an accessory splenic artery arising from the left gastric artery with submucosal intragastric course and supplying the upper pole of the spleen.

Embolic Brain Infarcts: A Rare Fatal Complication of Preoperative Embolization of a Massive Solitary Fibrous Tumor of the Pleura.

Solitary fibrous tumor of the pleura (SFTP) is a rare intrathoracic neoplasm, often giant in size and highly vascular, which can make surgical resection very challenging. Preoperative percutaneous embolization before surgical removal can significantly reduce the risk of uncontrollable intraoperative hemorrhage. However, a rare potential life threatening complication could result from embolization of SFTP and must be taken into consideration. This report describes a 69-year-old female with a large right thoracic SFTP, who underwent preoperative angiography and embolization and developed diffuse embolic brain infarcts immediately after the administration of polyvinyl alcohol particles.

Evolution of Multivalent Nanoparticle Adhesion via Specific Molecular Interactions.

The targeted delivery of nanoparticle carriers holds tremendous potential to transform the detection and treatment of diseases. A major attribute of nanoparticles is the ability to form multiple bonds with target cells, which greatly improves the adhesion strength. However, the multivalent binding of nanoparticles is still poorly understood, particularly from a dynamic perspective. In previous experimental work, we studied the kinetics of nanoparticle adhesion and found that the rate of detachment decreased over time. Here, we have applied the adhesive dynamics simulation framework to investigate binding dynamics between an antibody-conjugated, 200-nm-diameter sphere and an ICAM-1-coated surface on the scale of individual bonds. We found that nano adhesive dynamics (NAD) simulations could replicate the time-varying nanoparticle detachment behavior that we observed in experiments. As expected, this behavior correlated with a steady increase in mean bond number with time, but this was attributed to bond accumulation only during the first second that nanoparticles were bound. Longer-term increases in bond number instead were manifested from nanoparticle detachment serving as a selection mechanism to eliminate nanoparticles that had randomly been confined to lower bond valencies. Thus, time-dependent nanoparticle detachment reflects an evolution of the remaining nanoparticle population toward higher overall bond valency. We also found that NAD simulations precisely matched experiments whenever mechanical force loads on bonds were high enough to directly induce rupture. These mechanical forces were in excess of 300 pN and primarily arose from the Brownian motion of the nanoparticle, but we also identified a valency-dependent contribution from bonds pulling on each other. In summary, we have achieved excellent kinetic consistency between NAD simulations and experiments, which has revealed new insights into the dynamics and biophysics of multivalent nanoparticle adhesion. In future work, we will leverage the simulation as a design tool for optimizing targeted nanoparticle agents.

Comparison of the efficacy and tolerability of telmisartan and enalapril in patients of mild to moderate essential hypertension.

BACKGROUND: Theoretically, angiotensin II receptor blockers (ARBs) have certain advantages over angiotensin-converting enzyme inhibitors, but the contribution of these advantages to the clinical effect of ARBs is not known. OBJECTIVE: To compare the efficacy and tolerability of telmisartan with enalapril in patients of essential hypertension. MATERIALS AND METHODS: Patients of mild to moderate hypertension were randomized to receive either 40 mg of telmisartan or enalapril 10 mg once a day orally for 12 weeks. At each visit, the systolic blood pressure (BP), diastolic BP and heart rate of each patient were recorded. Investigations such as hemogram hemoglobin, total leucocytes count (Hb, TLC), serum creatinine, serum glutamic oxaloacetic transaminase, serum glutamic pyruric transaminase (SGOT, SGPT) random blood sugar and urine examination were performed at baseline and after 12 weeks of the treatment period. RESULTS: The mean reduction in systolic BP in the telmisartan/enalapril group was 26.38 ± 10.98/26.74 ± 8.24 mmHg while the mean reduction in diastolic BP in the telmisartan/enalapril group was 14 ± 2.98/9.71 ± 4.23 mmHg, respectively, at 12 weeks. When the reduction in systolic BP in the two groups was compared, there was no significant difference between the groups (P > 0.05). However, the mean reduction in diastolic BP achieved with telmisartan at 12 weeks was significantly higher (P < 0.001) than that achieved with enalapril after the corresponding period. The overall frequency of adverse-effects was similar. However, in the enalapril group, the incidence of dry cough was higher as compared to that in the telmisartan group (11.43% vs. 0%, respectively; P < 0.05). CONCLUSION: Telmisartan produces a greater reduction in diastolic BP than enalapril and is free from the adverse-effect of dry cough that is commonly encountered with enalapril.

The BRC repeats of human BRCA2 differentially regulate RAD51 binding on single- versus double-stranded DNA to stimulate strand exchange.

The breast and ovarian cancer suppressor BRCA2 controls the enzyme RAD51 during homologous DNA recombination (HDR) to preserve genome stability. BRCA2 binds to RAD51 through 8 conserved BRC repeat motifs dispersed in an 1127-residue region (BRCA2([BRC1-8])). Here, we show that BRCA2([BRC1-8]) exerts opposing effects on the binding of RAD51 to single-stranded (ss) versus double-stranded (ds) DNA substrates, enhancing strand exchange. BRCA2([BRC1-8]) alters the electrophoretic mobility of RAD51 bound to an ssDNA substrate, accompanied by an increase in ssDNA-bound protein assemblies, revealed by electron microscopy. Single-molecule fluorescence spectroscopy shows that BRCA2([BRC1-8]) promotes RAD51 loading onto ssDNA. In contrast, BRCA2([BRC1-8]) has a different effect on RAD51 assembly on dsDNA; it suppresses and slows this process. When homologous ssDNA and dsDNA are both present, BRCA2([BRC1-8]) stimulates strand exchange, with delayed RAD51 loading onto dsDNA accompanying the appearance of joint molecules representing recombination products. Collectively, our findings suggest that BRCA2([BRC1-8]) targets RAD51 to ssDNA while inhibiting dsDNA binding and that these contrasting activities together bolster one another to stimulate HDR. Our work provides fresh insight into the mechanism of HDR in humans, and its regulation by the BRCA2 tumor suppressor.