Cytochrome P450 reductase, antioxidant enzymes and cellular resistance to doxorubicin

Our data suggest that DOX resistance in P388/R-84 cells may result, at least in part, from reduced free radical formation by both suppression of flavin reductase(s) and overexpression of certain antioxidant enzymes such as GSH peroxidase and catalase. In addition, our results, in conjunction with other studies, indicate that flavin reductase(s) and antioxidant enzymes are differentially altered in cancer cells with acquired or de novo resistance to DOX. Further studies are needed, however, to elucidate the mechanism(s) by which the gene expression of these enzymes is regulated in drug-sensitive and -resistant cells.     

Phase I and pharmacokinetics studies of prochlorperazine 2-h i.v. infusion as a doxorubicin-efflux blocker

In an earlier phase I study, we reported that the maximal tolerated dose (MTD) of prochlorperazine (PCZ) given as a 15-min i.v. infusion was 75 mg/m². The highest peak plasma PCZ concentration achieved was 1100 ng/ml. The present study was conducted to determine if PCZ levels high enough to block doxorubicin (DOX) efflux in vitro could be achieved and sustained in vivo by increasing the duration of i.v. infusion from 15 min to 2 h. The treatment schedule consisted of i.v. prehydration with at least 500 ml normal saline (NS) and administration of a fixed standard dose of 60 mg/m² DOX as an i.v. bolus over 15 min followed by i.v. doses of 75, 105, 135, or 180 mg/m² PCZ in 250 ml NS over 2 h. The hematologic toxicities attributable to DOX were as expected and independent of the PCZ dose. Toxicities attributable to PCZ were sedation, dryness of mouth, anxiety, akathisia, hypotension, cramps, and confusion. The MTD of PCZ was 180 mg/m². Large interpatient variation in peak PCZ plasma levels (91–3215 ng/ml) was seen, with the plasma half-life (t1/2) being approximately 57 min in patients given 135–180 mg/m² PCZ. The volume of distribution (V_d), total clearance (Cl_T), and area under the curve (AUC) were 350.1±183.8 l/m², 260.7±142.7 l m² h^–1 and 1539±922 ng ml h^–1, respectively, in patients given 180 mg/m² PCZ and the respective values for patients receiving 135 mg/m² were 48.9±23.76 l/m², 33.2±2.62 l m² h^–1, and 4117±302 ng ml h^–1. High PCZ plasma levels (>600 ng/ml) were sustained in all patients treated with 135 mg/m² PCZ for up to 24 h. DOX plasma elimination was biphasic at 135 and 180 mg/m² PCZ, and a>10-ng/ml DOX plasma level was maintained for 24 h. Partial responses were seen in three of six patients with malignant mesothelioma, in two of ten patients with non-small-cell lung carcinoma, and in the single patient with hepatoma. Our data show that PCZ can be safely given as a 2-h infusion at 135 mg/m² with clinically manageable toxicities. The antitumor activity of the combination of DOX and PCZ needs to be confirmed in phase II trials.This work was supported by NIH grant R01 CA-29360 and S1488, CRC grant M01 RR-05280, and the Joan Levy Cancer Foundation. This paper was presented at the meeting of the American Association for Cancer Research, Orlando, Florida, May 19–22, 1993     

Characterization of a unique cell line (LAZ 221) from human acute lymphocytic ("null" cell) leukemia.

A unique human cell line designated LAZ 221 has been established from the peripheral blood of a patient with acute lymphocytic leukemia of the "null" cell type. The cell line does not possess the Epstein-Barr virus nuclear antigen and has a karyotype of 45,XX,-9,-12,+(9q12q). Both the established cell line and the patient's uncultured blast cells share the same phenotypic markers. They both lack T-cell markers. They fail to form sheep erythrocyte rosettes and do not react with T-cell-specific antisera (TH1-, HTL-), nor do they possess B-cell markers. They do not form rosettes with erythrocytes sensitized with complement, and they are surface immunoglobulin negative. However, they do possess an HLA-D-related glycoprotein complex of 23,000 to 30,000 daltons, an la-like antigen. Thus, LAZ 221 shares the phenotype of the patient's uncultured blasts and is a cell line representative of about 75% of all human acute lymphocytic leukemias. In this respect it differs from previously described human hematopoietic cell lines.     

Upper Airway Obstruction in Patients with Goiter Studied by Flow Volume Loops and Effect of Thyroidectomy

The patient with goiter and his or her physician frequently overlook symptoms of upper respiratory obstruction. Conventional radiology is the accepted method for detecting upper airway obstruction in these patients. Flow volume loops provide additional information on airflow dynamics. Twenty-five patients of goiter undergoing surgery were evaluated for upper airway obstruction by symptomatology, conventional radiology, and flow volume loops. Flow volume loops were repeated 1 month after surgery. Ten (40%) patients had mild symptoms on direct questioning. Tracheal deviation, compression, or both were noted in eight (32%) patients on radiology. Flow volume loops detected upper airway obstruction in 15 (60%) patients. Surgery resulted in normalization of all preoperative abnormal curves. The flow volume loop is a simple noninvasive method for detecting upper airway obstruction in patients with goiter. Abnormal upper airway dynamics are present in more patients with goiter than previously recognized, and relief of this obstruction should be an important aspect of thyroid surgery.     

Study of molar properties of GO after doping with transition metals for photodegradation of fluorescent dyes

We synthesized graphene oxide (GO) doped with transition metal ions and characterized it using XPS, FT-IR, TGA/DTG, XRD, SEM, AFM, ICP-OES, UV/vis, and Raman spectroscopy. An intrinsic viscosity [η] of 0.002–0.012 g% @ 0.002 aq-GO was determined for viscosity average molecular weight (M_v) of GO at 288.15, 298.15, and 308.15 K. Mark–Houwink (M–H) constants k (cm³ g⁻¹) and a (cm³ mol g⁻²) were calculated for 5–15 mg/100 mL polyvinylpyrrolidone (PVP), using 29, 40, 55 kg mol⁻¹ as markers for calculating M_v by fitting the [η] to the Mark–Houwink–Sakurada equation (MHSE). We obtained 48 134.19 g mol⁻¹M_v at 298.15 K, and the apparent molar (V_ϕm, cm³ mol⁻¹), limiting molar volumes (V⁰_GO)_{G$\stackrel{⃑}{O}$0}, enthalpy (ΔH_m, J mol⁻¹), entropy (ΔS_m, J mol⁻¹ K⁻¹), viscosity (η_m, mPa s mol⁻¹), surface tension (γ_m, mN m⁻¹ mol⁻¹), friccohesity (σ_m, scm⁻¹ mol⁻¹), fractional volume (ϕ_m, cm³ mol⁻¹), isentropic compressibility (K_sϕ,m, 10⁻⁴ cm s² g⁻¹ mol), infer GO molar consistency throughout the chemical processes. Molar properties (MPs) infer a GO monodispersion producing negative electrons (e⁻) and positive holes (h⁺) under sunlight. The transition metal ions (Fe²⁺, Mn²⁺, Ni²⁺, Cr³⁺, TMI) doped onto GO (TMI-GO), can photodegrade methylene blue (MB) in 60 min compared with 120 min using GO alone. The 4011 C atoms, 688 hexagonal sheets, 222 π-conjugations, and 4011 FE were calculated from the 48 134.19 g mol⁻¹. The functional edges are the negative and positive holes generating centres of the GO 2D sheets.

We synthesize and characterise graphene oxide doped with transition metal ions, and calculate the Mark–Houwink constants, determining methylene blue degradation efficiency.     

Podophyllum hexandrum Offers Radioprotection by Modulating Free Radical Flux: Role of Aryl-Tetralin Lignans

We have evaluated the effect of variation in aryl-tetralin lignans on the radioprotective properties of Podophyllum hexandrum. Two fractionated fractions of P. hexandrum [methanolic (S1) and chloroform fractions (S2)], with varying aryl-tetralin lignan content were utilized for the present study. The peroxyl ion scavenging potentials of S1 and S2 were found to be comparable [i.e. 45.88% (S1) and 41% (S2)] after a 48 h interval in a time-dependent study, whereas in a 2 h study, S2 exhibited significant (P < 0.05) antioxidant activity in different metal ion + flux states. In the aqueous phase, S2 exhibited non-site-specific reactive oxygen species scavenging activity, i.e. 73.12% inhibition at 500 mug ml(-1). S1 exhibited 58.40 +/- 0.8% inhibition (at 0.025 mug ml(-1)) of the formation of reactive nitrite radicals, comparable to S2 (52.45 +/- 0.825%), and also showed 45.01% site-specific activity (1000 mug ml(-1)), along with significant (P < 0.05) electron donation potential (50-2000 mug ml(-1)) compared to S2. Such activities of S1 could be attributed to the significantly (P < 0.05) higher levels of podophyllotoxin beta-d-glucopyranoside (16.5 times) and demethyl podophyllotoxin glucoside (2.9 times) compared with S2. Together, these findings clearly prove that aryl-tetralin lignan content influences the radiation protective potential of the Podophyllum fractions to a great extent.     

Angiotensin-Receptor Blockade Improves Inflammation and Endothelial Dysfunction in Ankylosing Spondylitis: ARB-AS Study

Cardiovascular (CV) disease is the leading cause of premature death in ankylosing spondylitis (AS). Atherosclerosis and AS share similar pathogenic mechanisms. The proven benefits of angiotensin-receptor blockers (ARBs) in atherosclerotic cardiovascular disease and their role in immune mediation provide strong rationale to investigate its impact with olmesartan on inflammation and endothelial dysfunction in AS. To investigate the effect of olmesartan on inflammation and endothelial dysfunction in AS. 40 AS patients were randomized to receive 24 weeks of treatment with olmesartan (10 mg/day, n  = 20) and placebo ( n  = 20) as an adjunct to existing stable antirheumatic drugs. Markers of endothelial function included the following: flow-mediated dilation (FMD) assessed by AngioDefender, endothelial progenitor cells (EPCs) estimated by flow cytometry, nitrite (nitric oxide surrogate), intracellular adhesion molecule-1 (ICAM-1) and vascular cell adhesion molecule-1 (VCAM-1) and inflammatory measures including Bath ankylosing spondylitis disease activity index (BASDAI), ankylosing spondylitis disease activity score (ASDAS) and bath ankylosing spondylitis functional index (BASFI); erythrocyte sedimentation rate (ESR) and C-reactive protein (CRP); proinflammatory cytokines (interleukin-1 [IL-1], IL-6, tumor necrosis factor-α [TNF-α]) and marker of oxidative stress– thiobarbituric acid reactive substances (TBARS) estimated at baseline and after treatment. Health assessment questionnaire disability index (HAQDI), 36-item short form survey (SF-36), and systematic coronary risk evaluation (SCORE) were estimated using standard tools. FMD improved significantly in the olmesartan group (5.83 ± 0.31% to 7.68 ± 0.27%, p  ≤  0.05) as compared with placebo (5.89 ± 0.35% to 6.04 ± 0.32%, p  = 0.33). EPC population, nitrite, VCAM-1, and TBARS levels improved significantly in olmesartan group as compared with placebo ( p ≤ 0.05). Olmesartan significantly decreased ASDAS, BASDAI, BASFI, ESR, CRP, IL-6, TNF-α, and SCORE as compared with placebo. HAQDI and SF-36 (PH) scores improved significantly in olmesartan group as compared with placebo. Olmesartan reduces inflammatory disease activity, improves quality of life (QOL), and decreases CV risk demonstrating the immunomodulatory, vasculoprotective, and cardioprotective potential of this drug in AS.     

Ag2O nanoparticle-catalyzed substrate-controlled regioselectivities: direct access to 3-ylidenephthalides and isocoumarins

Herein, we disclose the first example of an efficient, silver oxide nanoparticle-catalyzed, direct regioselective synthesis of 3-ylidenephthalides 11–16 and isocoumarins 17–20via sonogashira type coupling followed by substrate-controlled 5-exo-dig or 6-endo-dig cyclization reaction, respectively. This one pot coupling involves reaction of substituted 2-halobenzoic acid with meta/para-substituted and ortho-substituted terminal alkynes, which proceeded in a regioselective manner resulting in the formation of 3-ylidenephthalides or isocoumarins, respectively, in excellent yields (up to 95%) with complete Z-selectivity. This protocol features relatively broad substrate scope, mild conditions, operational simplicity, and is favourable with aromatic/alicyclic terminal alkynes. The competition experiments and gram-scale synthesis further highlight the importance and versatility of the methodology. The proposed mechanistic pathways illustrate that the regioselectivity is substantially being controlled by the substituent(s) present on the acetylenic phenyl ring.

We report the first example of an efficient, Ag₂O nanoparticle-catalyzed, direct regioselective synthesis of 3-ylidenephthalides and isocoumarins via Sonogashira type coupling followed by substrate-controlled 5-exo-dig or 6-endo-dig cyclization reaction, respectively.     

Recombinant activated factor VII in post partum haemorrhage

Post-partum haemorrhage (PPH) is a life-threatening obstetric complication and the leading cause of maternal death. Any bleeding that results in or could result in haemodynamic instability, if untreated, must be considered as PPH. There is no controversy about the need for prevention and treatment of PPH. The keystone of management of PPH entails first, non-invasive and nonsurgical methods and then invasive and surgical methods. However, mortality remains high. Therefore, new advancements in the treatment are most crucial. One such advancement has been the use of recombinant activated factor VII (rFVIIa) in PPH. First used 12 years back in PPH, this universal haemostatic agent has been effectively used in controlling PPH. The best available indicator of rFVIIa efficacy is the arrest of haemorrhage, which is judged by visual evidence and haemodynamic stabilization. It also reduces costs of therapy and the use of blood components in massive PPH. In cases of intractable PPH with no other obvious indications for hysterectomy, administration of rFVIIa should be considered before surgery. We share our experience in a series of cases of PPH, successfully managed using rFVIIa.