ABSTRACT
Much attention has been gained on green silver nanoparticles (green-AgNPs) in the medical field due to their remarkable effects against multi-drug resistant (MDR) microorganisms and targeted cancer treatment. In the current study, we demonstrated a simple and environment-friendly (i.e., green) AgNP synthesis utilizing Jacobaea maritima aqueous leaf extract. This leaf is well-known for its medicinal properties and acts as a reducing and stabilizing agent. Nanoparticle preparation with the desired size and shape was controlled by distinct parameters; for instance, temperature, extract concentration of salt, and pH. The characterization of biosynthesized AgNPs was performed by the UV-spectroscopy technique, dynamic light scattering, scanning electron microscopy, X-ray diffraction, and Fourier-transform infrared. The successful formation of AgNPs was confirmed by a surface plasmon resonance at 422 nm using UV-visible spectroscopy and color change observation with a particle size of 37± 10 nm and a zeta potential of -10.9 ± 2.3 mV. SEM further confirmed the spherical size and shape of AgNPs with a size varying from 28 to 52 nm. Antibacterial activity of the AgNPs was confirmed against all Gram-negative and Gram-positive bacterial reference and MDR strains that were used in different inhibitory rates, and the highest effect was on the E-coli reference strain (MIC = 25 µg/mL). The anticancer study of AgNPs exhibited an IC50 of 1.37 µg/mL and 1.98 µg/mL against MCF-7 (breast cancer cells) and A549 (lung cancer cells), respectively. Therefore, this green synthesis of AgNPs could have a potential clinical application, and further in vivo study is required to assess their safety and efficacy.
Subject(s)
Asteraceae , Metal Nanoparticles , Silver/chemistry , Metal Nanoparticles/chemistry , Microbial Sensitivity Tests , Spectroscopy, Fourier Transform Infrared , Anti-Bacterial Agents/chemistry , Plant Extracts/pharmacology , Plant Extracts/chemistry , Green Chemistry Technology/methodsABSTRACT
BACKGROUND: NB-UVB has long been the vitiligo management pillar with capability of achieving the main treatment outcomes; repigmentation and stabilization. Its stabilizing effect in dark skin has been debatable. However, randomized controlled trials regarding NB-UVB ability to control disease activity are lacking. PURPOSE: To assess stabilizing effect of NB-UVB in comparison to systemic corticosteroids, the mainstay in vitiligo stabilization, in skin photo-types (III-V). METHODS: This is a multicenter, placebo-controlled, randomized, prospective study. Eighty patients with active nonsegmental vitiligo (NSV) (Vitiligo disease activity (VIDA) ≥2) were randomized to either NB-UVB and placebo (NB-placebo) or NB-UVB and dexamethasone oral mini-pulse (OMP) therapy (NB-OMP) for 6 months. Sixty four patients completed the study, 34 in the NB-OMP group and 30 in the NB-placebo group. Patients were evaluated fortnightly according to presence or absence of symptoms/signs of activity. RESULTS: In spite of earlier control of disease activity observed in the NB-OMP group, it was comparable in both groups by the end of the study period. Disease activity prior to therapy, but not extent, was found to influence control of activity in both groups. Thus, NB-UVB is a safe sole therapeutic tool in vitiligo management. Not only does it efficiently achieve repigmentation, but also it is a comparable stabilizing tool for systemic corticosteroids in spite of slightly delayed control. CONCLUSION: NB-UVB is the only well-established vitiligo therapy that can be used solely whenever corticosteroids are contraindicated or immune-suppression is unjustified. Nonetheless, its combination with corticosteroids expedites response and improves compliance.
Subject(s)
Ultraviolet Therapy , Vitiligo , Combined Modality Therapy , Humans , Prospective Studies , Skin Pigmentation , Treatment Outcome , Vitiligo/drug therapy , Vitiligo/radiotherapyABSTRACT
OBJECTIVE: Prestin is an outer hair cell (OHC) protein responsible for increasing cochlear sensitivity and has been proposed as a biomarker. We aimed to evaluate whether the serum prestin level is related to the severity of chronic sensorineural hearing loss (SNHL). METHODS: Ninety subjects were recruited from the patient base at Samarra public hospitals and clinics in Iraq from January to October of 2022. They were divided into three groups equally: a group of healthy people without hearing loss (G0), a group with moderate SNHL (G1), and a group with severe SNHL (G2). The subjects ranged from 20 to 80 years of age and included 51 males and 39 females. Blood samples were collected, then serum was separated, and enzyme-linked immunosorbent assays were performed to quantify the levels of prestin. RESULTS: Hearing thresholds were sequentially statistically higher across the three groups. While prestin levels were significantly higher in G1 and G2 than that in G0, there were no differences between the G1 and G2 levels. Serum prestin levels were positively correlated with hearing thresholds in G1, but not G2. CONCLUSION: Our results suggest that in the clinical setting, prestin is sensitive to chronic mild to moderate SNHL (i.e., up to 40-60 dB), not more severe loss. This range is consistent with the added sensitivity provided by OHCs in the cochlea and provides support for prestin as a biomarker of OHC-mediated SNHL.
ABSTRACT
AIM: Evaluation of serum ferritin and vitamin D levels in females with chronic telogen effluvium (TE) or female pattern hair loss (FPHL), in order to validate their role in these common hair loss diseases. METHODS: Eighty females (18 to 45 years old) with hair loss, in the form of TE or FPHL, and 40 age-matched females with no hair loss were included in the study. Diagnosis was based upon clinical examination as well as trichogram and dermoscopy. Serum ferritin and vitamin D2 levels were determined for each participant. RESULTS: Serum ferritin levels in the TE (14.7 ± 22.1 µg/l) and FPHL (23.9 ± 38.5 µg/l) candidates were significantly lower than in controls (43.5 ± 20.4 µg/l). Serum vitamin D2 levels in females with TE (28.8 ± 10.5 nmol/l) and FPHL (29.1 ± 8.5 nmol/l) were significantly lower than in controls (118.2 ± 68.1 nmol/l; p < 0.001). These levels decreased with increased disease severity. Serum ferritin cut-off values for TE and FPHL were 27.5 and 29.4 µg/l, respectively, and those for vitamin D were 40.9 and 67.9 nmol/l. CONCLUSION: Low serum ferritin and vitamin D2 are associated with hair loss in females with TE and FPHL. Screening to establish these levels in cases of hair loss and supplementing with them when they are deficient may be beneficial in the treatment of disease.
Subject(s)
Alopecia/blood , Ergocalciferols/blood , Ferritins/blood , Adolescent , Adult , Female , Humans , Middle Aged , Young AdultABSTRACT
Background: Methicillin-resistant Staphylococcus aureus (MRSA), affecting livestock and human beings, has become a global public health hazard with economic consequences. Aims: The current study was designed to investigate the prevailing MRSA-associated subclinical mastitis and associated risk factors in dairy buffaloes. The study also highlighted the genetic variations and in silico-based proteomic differences among MRSA isolates. Methods: Out of 516 milk samples, 45.93% (237/516) were found positive for subclinical mastitis, while the prevalence of S. aureus was recorded 56.12%. The methicillin resistance in S. aureus isolates was evaluated by oxacillin disc diffusion test and molecular identification of the mecA gene. Results: The results revealed a phenotypic and molecular prevalence of MRSA at 45.11% and 18.79%, respectively. The risk factor analysis revealed that among various assumed risk factors, parity, milking hygiene, milker care during milking, milk yield, housing system, and floor type were significantly associated with subclinical mastitis in buffaloes. The sequencing and phylogenetic analysis showed no significant genetic variations among study isolates and depicted a high similarity with isolates from Africa, USA, India, Italy, Turkey, and Iran. The in-silico protein analysis showed that all sequences had the same protein motifs resembling penicillin protein 2a except Buff-13, whose protein structure resembles alpha-catenin-like protein hmp-1. Conclusion: The current study was the first report of the genotypic characterization and in silico protein analysis of MRSA from dairy buffaloes in Pakistan. The result highlighted the importance of antimicrobial resistance (AMR) and development of control strategies against MRSA infections.
ABSTRACT
Donor-specific HLA alloantibodies may cause acute and chronic antibody-mediated rejection (AMR) and significantly compromise allograft survival. The clinical relevance of antibodies directed against some HLA class II antigens, particularly HLA-DP, is less clear with conflicting reports on their pathogenicity. We report two patients with high levels of pretransplant donor-specific HLA-DP antibodies who subsequently developed recurrent acute AMR and graft failure. In both cases, there were no other donor-specific HLA alloantibodies, suggesting that the HLA-DP-specific antibodies may be directly pathogenic.
Subject(s)
Graft Rejection/immunology , HLA-DP Antigens/immunology , Kidney Transplantation , Adult , Humans , MaleABSTRACT
Spleen is highly vascularized organ and bleeding control during partial splenectomy is a big challenge. In this study conventional methods of electrocautery, absorbable suturing and advance methods of topical hemostat Surgicel® were compared to control bleeding during partial splenec- tomy. Twelve healthy dogs (n=4) were divided in A, B and C groups. After partial splenectomy Surgicel®, electrocautery and absorbable horizontal mattress sutures were used to control hemor- rhages in group A, B and C respectively. Bleeding time and loss of blood volume was evaluated during surgery. In addition, blood samples were taken on day 0 pre-surgery and on days 3, 10 and 17 post-surgery to evaluate changes in biochemical parameters after the application of dif- ferent hemostatic techniques. Ultrasonography was also performed at alternative days to check any gross changes in the spleen. Dogs in group A showed minimum bleeding time and loss of blood volume as compared to group B and C. Drop in red blood cells count was compared be- tween group A, B and C showing significant change (p≤0.05) at day 3, 10 and 17, while a sig- nificant decline in hemoglobin was found in group C followed by groups B and A at 3rd and 10th day. There was no difference between platelet counts in various groups. Ultrasonography showed no significant changes in the spleen parenchyma. It was concluded that Surgicel® was an effective material for controlling hemorrhage in veterinary patients.
Subject(s)
Blood Loss, Surgical/veterinary , Cellulose, Oxidized/pharmacology , Hemostasis, Surgical/veterinary , Spleen/surgery , Splenectomy/veterinary , Animals , Blood Loss, Surgical/prevention & control , Cellulose, Oxidized/administration & dosage , Dog Diseases , Dogs , Hemostasis, Surgical/methods , Hemostatics/administration & dosage , Hemostatics/pharmacology , Splenectomy/methodsABSTRACT
The present study aimed to explore a new source of montmorillonite and to develop an extraction and purification protocol for its isolation from raw clay samples acquired from the Koh-e-Suleiman mountain range in Pakistan. The process involved the collection of raw clay from the source, identification and quantification of montmorillonite. Granulometric extraction and purification protocols increased the montmorillonite content from 21.8-25.1% in the raw clay to 90.1-93.9% after small-scale extraction and 85.33-89.33% on a larger scale. A techno-economic analysis highlighted the practicality and economic benefits of large-scale extraction for industrial applications. This study highlights the existence of a substantial new source of this valuable clay which is currently used across multiple industries including construction, pottery making, pharmaceuticals, cosmetics and engineering. It is intuitively expected that the large-scale extraction of the material will improve the economic condition of the region by providing employment opportunities to locals and may be a valuable resource for export.
ABSTRACT
A 35 years old male living in Jamalpur district of Bangladesh working as a shopkeeper presented with dyspnea, fatigue, occasional fever and cough for two years. He did not give any history of hemoptysis or weight loss. He was smoker and non-alcoholic. He had a soft systolic murmur over pulmonary area and wide fixed splitting of the second heart sound. An Atrial septal defect (ASD) was detected by echocardiography. The patient had high circulating eosinophil count and Complement Fixation Test for filarial antibody revealed positive result. Moreover the patient's response to drug Diethylcarbamazime indicated suspected tropical pulmonary eosinophilia with Atrial Septal Defect.
Subject(s)
Heart Septal Defects, Atrial/complications , Heart Septal Defects, Atrial/surgery , Pulmonary Eosinophilia/complications , Adult , Heart Septal Defects, Atrial/diagnosis , Humans , Male , Pulmonary Eosinophilia/diagnosis , Pulmonary Eosinophilia/surgeryABSTRACT
Alkylation of 2-methylthiopyrimidin-4(1H)-one (1a) and its 5(6)-alkyl derivatives 1b-d as well as theophylline (7) with 2,2-bis(bromomethyl)-1,3-diacetoxypropane (2) under microwave irradiation gave the corresponding acyclonucleosides 1-[(3-acetoxy-2-acetoxymethyl-2-bromomethyl)prop-1-yl]-2-methyl-thio pyrmidin-4(1H)-ones 3a-d and 7-[(3-acetoxy-2-acetoxymethyl-2-bromomethyl)prop-1-yl]theophylline (8), which upon further irradiation gave the double-headed acyclonucleosides 1,1 '-[(2,2-diacetoxymethyl)-1,3-propylidene]-bis[(2-(methylthio)-pyrimidin-4(1H)-ones] 4a-c, and 7,7 '-[(2,2-diacetoxymethyl)-1,3-propylidene]-bis(theophylline) (9). The deacetylated derivatives were obtained by the action of sodium methoxide. The activity of deacetylated nucleosides against Hepatitis B virus was evaluated. Compound 5b showed moderate inhibition activity against HBV with mild cytotoxicity.
Subject(s)
Antiviral Agents/chemistry , Antiviral Agents/pharmacology , Hepatitis B virus/drug effects , Pyrimidine Nucleosides/chemistry , Pyrimidine Nucleosides/pharmacology , Pyrimidinones/chemistry , Theophylline/chemistry , Antiviral Agents/chemical synthesis , Cells, Cultured , Humans , Microwaves , Pyrimidine Nucleosides/chemical synthesis , Pyrimidinones/chemical synthesis , Pyrimidinones/pharmacologyABSTRACT
Sirtuins (SIRT) have been regarded as culprits in the pathogenesis of various diseases. Their exact role has not been explained. This study aimed to assess the expression of SIRT1, SIRT6, tumor necrosis factor (TNF)-α, and interferon (IFN)-γ in psoriatic patients. Thirty psoriatic patients and 22 controls were enrolled. Clinical examination and Psoriasis Area and Severity Index (PASI) were obtained. Two skin biopsies (lesional, peri-lesional) and one from controls were obtained. Tissue levels of SIRT1, SIRT6, TNF-α, and IFN-γ were measured using ELISA. SIRT1 was significantly lower in lesional skin with gradual increase in perilesional followed by control skin (P <0.001). SIRT6, TNF-α, and IFN-γ were significantly higher in lesional than perilesional and control skin (P <0.001). Significant positive correlations were found between SIRT1 and TNF-α, IFN-γ and between SIRT6 and TNF-α in peri-lesional skin. SIRT1 and SIRT6 are potentially involved in the pathogenesis of psoriasis. Modulating their action could offer a novel therapy for such disease.
Subject(s)
Interferon-gamma/metabolism , Psoriasis/metabolism , Sirtuin 1/metabolism , Sirtuins/metabolism , Tumor Necrosis Factor-alpha/metabolism , Adolescent , Adult , Aged , Case-Control Studies , Female , Humans , Male , Middle Aged , Skin/metabolism , Young AdultABSTRACT
Our previous studies have shown that subthreshold concentrations of two platelet agonists exert synergistic effects on platelet aggregation. Here we studied the mechanism of synergistic interaction of 5-hydroxytryptamine (5-HT) and epinephrine mediated platelet aggregation. We show that 5-HT had no or little effect on aggregation but it did potentiate the aggregation response of epinephrine. The synergistic interaction of 5-HT (1-5 microM) and epinephrine (0.5-2 microM) was inhibited by alpha2-adrenoceptor blocker (yohimbine; IC50= 0.4 microM), calcium channel blockers (verapamil and diltiazem with IC50 of 10 and 48 mM, respectively), PLC inhibitor (U73122; IC50=6 microM) and nitric oxide (NO) donor, SNAP (IC50=1.6 microM)). The data suggest that synergistic effects of platelet agonists are receptor-mediated and occur through multiple signalling pathways including the activation PLC/Ca2+ signalling cascades.
Subject(s)
Calcium Signaling , GTP-Binding Protein alpha Subunits, Gi-Go/metabolism , GTP-Binding Proteins/metabolism , Platelet Aggregation/drug effects , Type C Phospholipases/metabolism , Blotting, Western , Calcium Channel Blockers/pharmacology , Drug Synergism , Enzyme Activation , Enzyme Inhibitors/pharmacology , Epinephrine/pharmacology , Humans , Platelet Aggregation/physiology , Serotonin/pharmacology , Signal Transduction , Type C Phospholipases/antagonists & inhibitorsABSTRACT
Our recent studies have shown that co-activation of Gq and Gi proteins by 5-hydroxytryptamine (5-HT) and adrenaline show synergism in human platelet aggregation. This study was conducted to examine the mechanism(s) of synergistic interaction of 5-HT and platelet activating factor (PAF) in human platelets. We show that PAF, but not 5-HT, increased platelet aggregation in a concentration-dependent manner. However, low concentrations of 5-HT (2 microM) potentiated platelet aggregation induced by subthreshold concentration of PAF (40 nM) indicating a synergistic interaction between the two agonists and this synergism was blocked by receptor antagonists to either 5-HT or PAF. 5-HT also potentiated the effect of PAF on thromboxane A2 (TXA2) formation and phosphorylation of extracellularly regulated mitogen-activated protein kinases (ERK1/2). The synergism of 5-HT and PAF in platelet aggregation was inhibited by calcium (Ca2+) channel blockers, verapamil and diltiazem, phospholipase C (PLC) inhibitor, U73122, cyclooxygenase (COX) inhibitor, indomethacin, and MEK inhibitor, PD98059. These data suggest that synergistic effect of 5-HT and PAF on human platelet aggregation involves activation of PLC/Ca2+, COX and MAP kinase pathways.
Subject(s)
Platelet Activating Factor/pharmacology , Platelet Aggregation/drug effects , Serotonin/pharmacology , Diltiazem/pharmacology , Dose-Response Relationship, Drug , Drug Synergism , Estrenes/pharmacology , Flavonoids/pharmacology , Humans , In Vitro Techniques , Indomethacin/pharmacology , Kinetics , Mitogen-Activated Protein Kinases/metabolism , Phosphorylation/drug effects , Platelet Activation/drug effects , Platelet Aggregation/physiology , Pyrrolidinones/pharmacology , Thromboxane A2/biosynthesis , Verapamil/pharmacologyABSTRACT
We investigated the combined effect of 5-hydroxytryptamine (5-HT, serotonin) and calcium ionophore (A23187) on human platelet aggregation. Aggregation, monitored at 37 degrees C using a Dual-channel Lumi-aggregometer, was recorded for 5 min after challenge by a change in light transmission as a function of time. 5-HT (2-200 microM) alone did not cause platelet aggregation, but markedly potentiated A23187 (low dose) induced aggregation. Inhibitory concentration (IC50) values for a number of compounds were calculated as means +/- SEM from dose-response determinations. Synergism between 5-HT (2-5 microM) and A23187 (0.5-2 microM) was inhibited by 5-HT receptor blockers, methysergide (IC50 = 18 microM) and cyproheptadine (IC50 = 20 microM), and calcium channel blockers (verapamil and diltiazem, IC50 = 20 microM and 40 microM respectively). Interpretation of the effects of these blockers is complicated by their lack of specificity. Similarly, U73122, an inhibitor of phospholipase C (PLC), blocked the synergistic effect at an IC50 value of 9.2 microM. Wortmannin, a phosphatidylinositide 3-kinase (PI 3-K) inhibitor, also blocked the response (IC50 = 2.6 microM). However, neither genistein, a tyrosine-specific protein kinase inhibitor, nor chelerythrine, a protein kinase C inhibitor, affected aggregation at concentrations up to 10 microM. We conclude that the synergistic interaction between 5-HT and ionophore may be mediated by activation of PLC/Ca2+ and PI 3-kinase signalling pathways, but definitive proof will require other enzyme inhibitors with greater specificity.
Subject(s)
Blood Platelets/drug effects , Calcimycin/pharmacology , Ionophores/pharmacology , Phosphatidylinositol 3-Kinases/physiology , Platelet Aggregation/drug effects , Second Messenger Systems/drug effects , Serotonin/pharmacology , Type C Phospholipases/physiology , Adult , Alkaloids , Androstadienes/pharmacology , Benzophenanthridines , Calcium Channel Blockers/pharmacology , Cyproheptadine/pharmacology , Diltiazem/pharmacology , Dose-Response Relationship, Drug , Drug Combinations , Drug Synergism , Enzyme Inhibitors , Estrenes/pharmacology , Female , Genistein/pharmacology , Humans , In Vitro Techniques , Male , Methysergide/pharmacology , Phenanthridines/pharmacology , Phosphoinositide-3 Kinase Inhibitors , Pyrrolidinones/pharmacology , Type C Phospholipases/antagonists & inhibitors , Verapamil/pharmacology , WortmanninABSTRACT
The ambident nucleophilic nature of the sodium salts of 2(1H)-qunioxalinone (2) and the phthalazinedione (3) has been realized from their alkylation with 2-(2-chloroethoxy)ethylacetate (1) to afford 1-[2-(2-acetoxyethoxy)ethyl]-2(1H)-quinoxalinone (8) and 2-[2-(2-acetoxyethoxy)ethoxy]qunioxaline (9) as well as 10 and 11, respectively. The corresponding derivatives 12-15 were similarly prepared by the alkylation of the unnatural bases 4-7 with 1. Treatment of the alkylated derivatives 8-15 with methanolic ammonia solution (1:1) at room temperature gave the corresponding hydroxyalkyl derivatives 16-23. The site of the alkylation was deduced from the spectral characteristics of the products. The activity of compounds 16-22 against Hepatitis B virus (HBV) in HepG2 cell has been tested. Some of the compounds showed high viral replication inhibition with low cytotoxicity.
Subject(s)
Acyclovir/analogs & derivatives , Acyclovir/pharmacology , Antiviral Agents/pharmacology , Hepatitis B virus/drug effects , Acyclovir/chemistry , Antiviral Agents/chemistry , Cell Line , DNA Replication/drug effects , DNA, Viral/biosynthesis , Humans , Magnetic Resonance Spectroscopy , Polymerase Chain ReactionABSTRACT
Two chemically synthesized piperidinium derivatives i.e l-methyl-1-(3,4) dihydroxy phenacyl-4-hydroxy piperidinium chloride and 1-methyl-(4-p) methoxy phenacyl 4-hydroxy piperidinium bromide have been evaluated for their analgesic activity in intact albino mice by tail immersion method because of their structural similarity with opioids. Both the compounds were administered in the doses of 50 mg/kg. The results were compared with pethidine used as the reference drug. The control animal received only the vehicle. The present study suggested that both the compounds exhibit significant analgesic activity.
Subject(s)
Islam , Kidney Transplantation , Religion and Medicine , Tissue and Organ Procurement , Transplantation , Humans , Patient Selection , Singapore , UncertaintyABSTRACT
The sodium salts of some hetaryls of the quinoxalin-2-ones 2-4, phthalazine-1,4-dione 5, phthalazin-1-one 6, and pyridazin-6-ones 7 and 8 were alkylated with (+/-) 2,3-O-isopropylidene-1-O-(4-toluenesulfonyl)glycerol (1) to give the respective tetraseco-nucleosides 9-15. Their deisopropylidenation with 70% acetic acid in water gave the corresponding 2,3-dihydroxyprop-1-yl hetaryls 16-22. Compounds 16-22 showed varying inhibition activity against Hepatitis B virus (HBV) with low to moderate cytotoxicity, where 18 and 21 showed the highest replication inhibition and low cytotoxicity.
Subject(s)
Antiviral Agents/chemical synthesis , Hepatitis B virus/drug effects , Propylene Glycols/chemical synthesis , Antiviral Agents/pharmacology , Cells, Cultured , DNA, Viral/biosynthesis , Humans , Polymerase Chain Reaction , Propylene Glycols/pharmacologyABSTRACT
This study was conducted to examine the mechanism(s) of synergistic interaction of histamine- and adrenaline-mediated human platelet aggregation. We found that platelet aggregation mediated by subthreshold concentrations of histamine (1-4 microm) plus adrenaline (0.5-2 microm) is inhibited by both an alpha(2)-adrenoceptor blocker (yohimbine) and a histamine (H1) receptor antagonist (diphenhydramine). In examining the role of the downstream signalling pathway, we found that such an interaction is inhibited by the calcium channel blockers verapamil and diltiazem. However, platelet aggregation by adrenaline plus histamine was inhibited by very low concentrations of the phospholipase C (PLC) inhibitor, U73122 (IC(50)= 1.2 microm), the MEK inhibitor, PD98059 (IC(50)= 1.1 microm) and the cyclo-oxygenase (COX) inhibitor, indomethacin (IC(50)= 7 microm). However the inhibition of receptor tyrosine kinase, protein kinase C and phosphatidylinositol 3-kinase by genistien, chelerythrine and wortmannin, respectively, had no significant effect on aggregation. Similarly the nitric oxide donor (SNAP) had no effect on this synergism. These data suggest that the synergistic effect of histamine and adrenaline during human platelet aggregation is receptor mediated and involves activation of PLC, COX and MAP kinase signalling pathways.
Subject(s)
Epinephrine/pharmacology , Histamine/pharmacology , Platelet Aggregation/drug effects , Drug Synergism , Estrenes/pharmacology , Humans , Mitogen-Activated Protein Kinases/metabolism , Phospholipases/metabolism , Platelet Aggregation/physiology , Platelet Aggregation Inhibitors/pharmacology , Prostaglandin-Endoperoxide Synthases/metabolism , Pyrrolidinones/pharmacology , Vasodilator Agents/pharmacology , Verapamil/pharmacologyABSTRACT
Methotrexate (MTX) in low doses is commonly used to treat rheumatoid arthritis (RA). At least 36 deaths have been attributed to bone marrow cytotoxicity associated with low dose MTX. The goal was to determine if plasma from arthritis patients taking low dose MTX induces platelet aggregation in platelet rich plasma from healthy volunteers. Plasma from patients on MTX alone caused a 3-fold increase in aggregation vs plasma from controls (P<0.05). Plasma from patients not taking MTX or taking MTX with diclofenac caused aggregation to a lesser extent. Diclofenac, along with several others NSAIDs and cyclooxygenase inhibitors, depressed aggregation produced by arachidonic acid in platelet rich plasma from healthy volunteers. A precise mechanism for amplification of aggregation by MTX plasma and its relationship to MTX toxicity remains unknown. However, a serum factor may be produced by MTX that modulates the activity of cyclooxygenase, thereby influencing aggregation.