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1.
Ann Oncol ; 34(3): 262-274, 2023 03.
Article in English | MEDLINE | ID: mdl-36535565

ABSTRACT

BACKGROUND: Patients with recurrent or metastatic head and neck squamous cell carcinoma (R/M HNSCC) have a poor prognosis. The phase III KESTREL study evaluated the efficacy of durvalumab [programmed death-ligand 1 (PD-L1) antibody] with or without tremelimumab [cytotoxic T-lymphocyte-associated antigen 4 (CTLA-4) antibody], versus the EXTREME regimen in patients with R/M HNSCC. PATIENTS AND METHODS: Patients with HNSCC who had not received prior systemic treatment for R/M disease were randomized (2 : 1 : 1) to receive durvalumab 1500 mg every 4 weeks (Q4W) plus tremelimumab 75 mg Q4W (up to four doses), durvalumab monotherapy 1500 mg Q4W, or the EXTREME regimen (platinum, 5-fluorouracil, and cetuximab) until disease progression. Durvalumab efficacy, with or without tremelimumab, versus the EXTREME regimen in patients with PD-L1-high tumors and in all randomized patients was assessed. Safety was also assessed. RESULTS: Durvalumab and durvalumab plus tremelimumab were not superior to EXTREME for overall survival (OS) in patients with PD-L1-high expression [median, 10.9 and 11.2 versus 10.9 months, respectively; hazard ratio (HR) = 0.96; 95% confidence interval (CI) 0.69-1.32; P = 0.787 and HR = 1.05; 95% CI 0.80-1.39, respectively]. Durvalumab and durvalumab plus tremelimumab prolonged duration of response versus EXTREME (49.3% and 48.1% versus 9.8% of patients remaining in response at 12 months), correlating with long-term OS for responding patients; however, median progression-free survival was longer with EXTREME (2.8 and 2.8 versus 5.4 months). Exploratory analyses suggested that subsequent immunotherapy use by 24.3% of patients in the EXTREME regimen arm contributed to the similar OS outcomes between arms. Grade 3/4 treatment-related adverse events (TRAEs) for durvalumab, durvalumab plus tremelimumab, and EXTREME were 8.9%, 19.1%, and 53.1%, respectively. CONCLUSIONS: In patients with PD-L1-high expression, OS was comparable between durvalumab and the EXTREME regimen. Durvalumab alone, and with tremelimumab, demonstrated durable responses and reduced TRAEs versus the EXTREME regimen in R/M HNSCC.


Subject(s)
Carcinoma, Squamous Cell , Head and Neck Neoplasms , Humans , Squamous Cell Carcinoma of Head and Neck/etiology , B7-H1 Antigen , Antineoplastic Combined Chemotherapy Protocols/therapeutic use , Neoplasm Recurrence, Local , Head and Neck Neoplasms/etiology
4.
Pharmacogenomics J ; 18(2): 245-250, 2018 04.
Article in English | MEDLINE | ID: mdl-28462920

ABSTRACT

Higher exposure to tenofovir (TFV) increases the risk for kidney function decline, but the impact of genetic factors on TFV exposure is largely unknown. We investigated whether single-nucleotide polymorphisms (SNPs, n=211) in 12 genes are potentially involved in TFV exposure. Participants (n=91) from the Women's Interagency HIV Study, underwent a 24 h intensive pharmacokinetic sampling of TFV after witnessed dose and TFV area under the time-concentration curves (AUCs) were calculated for each participant. SNPs were assayed using a combination of array genotyping and Sanger sequencing. Linear regression models were applied to logarithmically transformed AUC. Those SNPs that met an a priori threshold of P<0.001 were considered statistically associated with TFV AUC. ABCG2 SNP rs2231142 was associated with TFV AUC with rare allele carriers displaying 1.51-fold increase in TFV AUC (95% confidence interval: 1.26, 1.81; P=1.7 × 10-5). We present evidence of a moderately strong effect of the rs2231142 SNP in ABCG2 on a 24 h TFV AUC.


Subject(s)
ATP Binding Cassette Transporter, Subfamily G, Member 2/genetics , Anti-HIV Agents/therapeutic use , HIV Infections/drug therapy , HIV Infections/genetics , Neoplasm Proteins/genetics , Polymorphism, Single Nucleotide/genetics , Tenofovir/therapeutic use , Adult , Area Under Curve , Cohort Studies , Cross-Sectional Studies , Female , Humans , Middle Aged , Prospective Studies , Young Adult
5.
Ann Oncol ; 28(9): 2298-2304, 2017 Sep 01.
Article in English | MEDLINE | ID: mdl-28911072

ABSTRACT

BACKGROUND: Genomic profiling is increasingly incorporated into oncology research and the clinical care of cancer patients. We sought to determine physician perception and use of enterprise-scale clinical sequencing at our center, including whether testing changed management and the reasoning behind this decision-making. PATIENTS AND METHODS: All physicians who consented patients to MSK-IMPACT, a next-generation hybridization capture assay, in tumor types where molecular profiling is not routinely performed were asked to complete a questionnaire for each patient. Physician determination of genomic 'actionability' was compared to an expertly curated knowledgebase of somatic variants. Reported management decisions were compared to chart review. RESULTS: Responses were received from 146 physicians pertaining to 1932 patients diagnosed with 1 of 49 cancer types. Physicians indicated that sequencing altered management in 21% (331/1593) of patients in need of a treatment change. Among those in whom treatment was not altered, physicians indicated the presence of an actionable alteration in 55% (805/1474), however, only 45% (362/805) of these cases had a genomic variant annotated as actionable by expert curators. Further evaluation of these patients revealed that 66% (291/443) had a variant in a gene associated with biologic but not clinical evidence of actionability or a variant of unknown significance in a gene with at least one known actionable alteration. Of the cases annotated as actionable by experts, physicians identified an actionable alteration in 81% (362/445). In total, 13% (245/1932) of patients were enrolled to a genomically matched trial. CONCLUSION: Although physician and expert assessment differed, clinicians demonstrate substantial awareness of the genes associated with potential actionability and report using this knowledge to inform management in one in five patients. CLINICAL TRIAL NUMBER: NCT01775072.


Subject(s)
Gene Expression Profiling/statistics & numerical data , Genetic Association Studies/statistics & numerical data , High-Throughput Nucleotide Sequencing/statistics & numerical data , Neoplasms/genetics , Oncologists , Precision Medicine/psychology , Female , Humans , Male , Neoplasms/therapy , Nucleic Acid Hybridization , Perception
6.
Ann Oncol ; 28(10): 2533-2538, 2017 10 01.
Article in English | MEDLINE | ID: mdl-28961834

ABSTRACT

Background: Activating events along the PI3K/mTOR pathway are common in head and neck squamous cell carcinomas (HNSCC), and preclinical studies suggest additive or synergistic effects when combining mTORC1 inhibitors with carboplatin and paclitaxel chemotherapy. Patients and methods: In this single-institution phase II study, the combination of temsirolimus 25 mg, carboplatin AUC 1.5, and paclitaxel 80 mg/m2 administered on days 1 and 8 of a 21-day cycle was evaluated in 36 patients with recurrent and/or metastatic (R/M) HNSCC. The primary end point was objective response rate after two cycles of treatment. Secondary end points include the safety and tolerability profile and overall survival. Correlative studies with exome mutational analysis were performed in pre-treatment biopsy samples from 21 patients. Results: Fifteen (41.7%) patients had an objective response, which were all partial responses, and 19 (52.3%) patients had stable disease as best response. The two patients who were designated as 'non-responders' were removed from study prior to two cycles of treatment, but are included in the efficacy and safety analyses. The median duration on study was 5.3 months and the median progression-free survival and overall survival were 5.9 months (95% confidence interval, 4.8-7.1) and 12.8 months (95% confidence interval, 9.8-15.8), respectively. The most common grade 3 and 4 adverse events were hematologic toxicities. Three (3.8%) patients developed neutropenic fever on study. Three of four patients with PIK3CA mutations experienced tumor regressions, and responses were also seen in patients with other genetic alterations in the PI3K/mTOR pathway. Conclusion: The combination of temsirolimus with low-dose weekly carboplatin and paclitaxel appears to have meaningful clinical efficacy in the treatment of R/M HNSCC. This regimen has a relatively high response rate compared to other treatments evaluated in R/M HNSCC, and potential associations with genetic alterations in the PI3K/mTOR pathway should be further explored.


Subject(s)
Antineoplastic Combined Chemotherapy Protocols/administration & dosage , Carcinoma, Squamous Cell/drug therapy , Head and Neck Neoplasms/drug therapy , Neoplasm Recurrence, Local/drug therapy , Adult , Aged , Aged, 80 and over , Carboplatin/administration & dosage , Carcinoma, Squamous Cell/pathology , Dose-Response Relationship, Drug , Drug Administration Schedule , Female , Head and Neck Neoplasms/pathology , Humans , Male , Middle Aged , Neoplasm Metastasis , Neoplasm Recurrence, Local/pathology , Paclitaxel/administration & dosage , Sirolimus/administration & dosage , Sirolimus/analogs & derivatives , Squamous Cell Carcinoma of Head and Neck
7.
Ann Oncol ; 27(10): 1902-8, 2016 10.
Article in English | MEDLINE | ID: mdl-27566443

ABSTRACT

BACKGROUND: Recurrent/metastatic adenoid cystic carcinoma (ACC) is an incurable disease with no standard treatments. The majority of ACCs express the oncogenic transcription factor MYB (also c-myb), often in the context of a MYB gene rearrangement. This phase II trial of the tyrosine kinase inhibitor (TKI) axitinib (Pfizer) tested the hypothesis that targeting pathways activated by MYB can be therapeutically effective for ACC. PATIENTS AND METHODS: This is a minimax two-stage, phase II trial that enrolled patients with incurable ACC of any primary site. Progressive or symptomatic disease was required. Patients were treated with axitinib 5 mg oral twice daily; dose escalation was allowed. The primary end point was best overall response (BOR). An exploratory analysis correlating biomarkers to drug benefit was conducted, including next-generation sequencing (NGS) in 11 patients. RESULTS: Thirty-three patients were registered and evaluable for response. Fifteen patients had the axitinib dose increased. Tumor shrinkage was achieved in 22 (66.7%); 3 (9.1%) had confirmed partial responses. Twenty-five (75.8%) patients had stable disease, 10 of whom had disease stability for >6 months. The median progression-free survival (PFS) was 5.7 months (range 0.92-21.8 months). Grade 3 axitinib-related toxicities included hypertension, oral pain and fatigue. A trend toward superior PFS was noted with the MYB/NFIB rearrangement, although this was not statistically significant. NGS revealed three tumors with 4q12 amplification, producing increased copies of axitinib-targeted genes PDGFR/KDR/KIT. Two 4q12 amplified patients achieved stable disease for >6 months, including one with significant tumor reduction and the longest PFS on study (21.8 months). CONCLUSIONS: Although the primary end point was not met, axitinib exhibited clinical activity with tumor shrinkage achieved in the majority of patients with progressive disease before trial enrollment. Analysis of MYB biomarkers and genomic profiling suggests the hypothesis that 4q12 amplified ACCs are a disease subset that benefit from TKI therapy.


Subject(s)
Carcinoma, Adenoid Cystic/drug therapy , Imidazoles/administration & dosage , Indazoles/administration & dosage , NFI Transcription Factors/genetics , Protein Kinase Inhibitors/administration & dosage , Proto-Oncogene Proteins c-myb/genetics , Adult , Aged , Axitinib , Carcinoma, Adenoid Cystic/genetics , Carcinoma, Adenoid Cystic/pathology , Chromosomes, Human, Pair 4/genetics , Disease-Free Survival , Dose-Response Relationship, Drug , Drug-Related Side Effects and Adverse Reactions , Female , High-Throughput Nucleotide Sequencing , Humans , Imidazoles/adverse effects , Indazoles/adverse effects , Male , Middle Aged , Oncogene Proteins, Fusion/genetics , Protein Kinase Inhibitors/adverse effects
8.
Antimicrob Agents Chemother ; 60(8): 4684-9, 2016 08.
Article in English | MEDLINE | ID: mdl-27216053

ABSTRACT

Recent observational studies have suggested possible reductions in mortality in patients receiving cefazolin versus antistaphylococcal penicillins. We examined 90-day mortality in patients receiving cefazolin compared to nafcillin for methicillin-susceptible Staphylococcus aureus (MSSA) bloodstream infection (BSI). We identified persons with MSSA BSI admitted to San Francisco General Hospital from January 2008 to July 2013 through a hospital-wide infection surveillance system and confirmed 90-day mortality using U.S. national vital registries. We included persons receiving cefazolin or nafcillin as the predominant intravenous antimicrobial agent; all participants received inpatient Infectious Diseases service consultation. We estimated the association between receipt of cefazolin and 90-day risk of death by multivariate logistic regression, including a propensity score for receiving cefazolin as the second predictor. Of 230 MSSA BSI cases, 30 received nafcillin and 70 received cefazolin as the predominant antimicrobial; 10 died within 90 days, 5 from each group. Unadjusted analysis showed substantial but not statistically significant reduced odds of death in those receiving cefazolin (odds ratio, 0.38; 95% confidence interval [CI], 0.10 to 1.44). Multivariate analysis with propensity scores found a similar adjusted odds ratio (0.40; 95% CI, 0.09 to 1.74; P = 0.22). We found a large reduction in 90-day mortality in those receiving cefazolin compared to nafcillin for MSSA BSI, but this finding was not statistically significant. The magnitude of effect seen in this and other studies justifies further study.


Subject(s)
Bacteremia/drug therapy , Cefazolin/therapeutic use , Cross Infection/drug therapy , Methicillin/therapeutic use , Nafcillin/therapeutic use , Staphylococcal Infections/drug therapy , Staphylococcus aureus/drug effects , Anti-Bacterial Agents/therapeutic use , Bacteremia/microbiology , California , Cross Infection/microbiology , Female , Humans , Male , Middle Aged , Penicillins/therapeutic use , Tertiary Care Centers
9.
Int Braz J Urol ; 39(4): 565-71, 2013.
Article in English | MEDLINE | ID: mdl-24054385

ABSTRACT

PURPOSE: To investigate the anti-urolithiatic effect of cow urine ark (medicinal distilled cow urine) on ethylene glycol (EG) induced renal calculi. MATERIALS AND METHODS: 36 male Wistar rats were randomly divided into 6 equal groups. Group I animals served as vehicle control and received distilled water for 28 days. Group II to VI animals received 1% v/v EG in distilled water for 28 days. Group II served as EG control. Group III and IV (preventive groups) received cow urine ark orally for 28 days in doses of 1 mL/kg and 2 mL/kg, respectively. Group V and VI (treatment groups) received 1 mL/kg and 2 mL/kg cow urine ark orally, respectively from 15th to 28th days. 24-hour urine samples were collected on day 0 and 28. Urine volume and oxalate levels were measured. On day 28, blood was collected for biochemical parameters. Animals were sacrificed and kidneys were harvested, weighed and histopathologically evaluated for calcium oxalate (CaOx) crystals. To calculate the percentage of inhibition of mineralization, simultaneous flow static in-vitro model was used. RESULTS: EG significantly increased urine oxalate, serum creatinine, blood urea level; kidney weight and CaOx deposits. Provision of cow urine ark resulted in significantly lower levels of urine oxalate, serum creatinine, blood urea and CaOx depositions as compared to Group II. (p value < 0.05) It also significantly restored kidney weight. (p value < 0.05) Cow urine ark inhibited 40% and 35% crystallization of CaOx and calcium phosphate, respectively. CONCLUSION: Cow urine ark is effective in prevention and treatment of EG induced urolithiasis in Wistar rats.


Subject(s)
Kidney Calculi/drug therapy , Urine/chemistry , Animals , Cattle , Creatinine/analysis , Ethylene Glycol , Kidney Calculi/chemically induced , Kidney Calculi/pathology , Male , Organ Size , Random Allocation , Rats , Reproducibility of Results , Time Factors , Treatment Outcome , Urea/blood
10.
Int. braz. j. urol ; 39(4): 565-571, Jul-Aug/2013. tab, graf
Article in English | LILACS | ID: lil-687297

ABSTRACT

Purpose To investigate the anti-urolithiatic effect of cow urine ark (medicinal distilled cow urine) on ethylene glycol (EG) induced renal calculi. Materials and Methods 36 male Wistar rats were randomly divided into 6 equal groups. Group I animals served as vehicle control and received distilled water for 28 days. Group II to VI animals received 1% v/v EG in distilled water for 28 days. Group II served as EG control. Group III and IV (preventive groups) received cow urine ark orally for 28 days in doses of 1 mL/kg and 2 mL/kg, respectively. Group V and VI (treatment groups) received 1 mL/kg and 2 mL/kg cow urine ark orally, respectively from 15th to 28th days. 24-hour urine samples were collected on day 0 and 28. Urine volume and oxalate levels were measured. On day 28, blood was collected for biochemical parameters. Animals were sacrificed and kidneys were harvested, weighed and histopathologically evaluated for calcium oxalate (CaOx) crystals. To calculate the percentage of inhibition of mineralization, simultaneous flow static in-vitro model was used. Results EG significantly increased urine oxalate, serum creatinine, blood urea level; kidney weight and CaOx deposits. Provision of cow urine ark resulted in significantly lower levels of urine oxalate, serum creatinine, blood urea and CaOx depositions as compared to Group II. (p value < 0.05) It also significantly restored kidney weight. (p value < 0.05) Cow urine ark inhibited 40% and 35% crystallization of CaOx and calcium phosphate, respectively. Conclusion Cow urine ark is effective in prevention and treatment of EG induced urolithiasis in Wistar rats. .


Subject(s)
Animals , Cattle , Male , Rats , Kidney Calculi/drug therapy , Urine/chemistry , Creatinine/analysis , Ethylene Glycol , Kidney Calculi/chemically induced , Kidney Calculi/pathology , Organ Size , Random Allocation , Reproducibility of Results , Time Factors , Treatment Outcome , Urea/blood
12.
Diabetes Obes Metab ; 12(2): 133-8, 2010 Feb.
Article in English | MEDLINE | ID: mdl-19889003

ABSTRACT

OBJECTIVE: To evaluate the effects of intensive insulin therapy alone or with added pioglitazone on renal salt/water balance and body fluid compartment shifts in type 2 diabetes. METHODS: A total of 25 insulin-treated, obese patients with type 2 diabetes were randomized to pioglitazone 45 mg (n = 12) or placebo (n = 13) and treated intensively for 12-16 weeks to achieve equivalent glycaemic control. We measured total body water (TBW) and extracellular/intracellular fluid by bioimpedance analysis; plasma/RBC volume with I(131)albumin; sodium handling by fractional excretion of sodium/lithium (FeNa/FeLi) and other renal/hormonal parameters. RESULTS: Intensification of insulin therapy and the addition of pioglitazone significantly improved glycaemia (HbA1C 7.8-7.2% and 7.6-7.1%) and increased body weight (1.7 and 4.9 kg) respectively. TBW increased 1.7 l with insulin alone (65% intracellular) and 1.6 l with added pioglitazone (75% extracellular) (p = 0.06 and 0.09 respectively). Plasma volume increased 0.2 +/- 0.1 l with insulin alone (p = 0.05) and 0.4 +/- 0.1 l with added pioglitazone (p < 0.05). Extravascular, extracellular (interstitial) fluid increased significantly and more with added pioglitazone (0.8 +/- 0.2 l, p < 0.01) than with insulin alone (0.4 +/- 0.2 l, p = ns). At steady-state, FeLi (marker of proximal-tubular sodium delivery to the distal nephron) increased significantly with added pioglitazone (12.4 +/- 1.3 to 18.0 +/- 3.2%) vs. no significant change with insulin alone (15.4 +/- 1.2 to 14.5 +/- 2.3%). There were no significant changes in the other parameters. CONCLUSION: In intensively insulin-treated obese type 2 diabetic patients, at equivalent glycaemic control, the addition of pioglitazone causes greater weight gain, but a similar increase in body water that is mainly extracellular and interstitial compared with intracellular increase with insulin therapy alone. Pioglitazone also increases the filtered load of sodium reabsorbed at the distal nephron with no net change in FeNa.


Subject(s)
Body Water/drug effects , Diabetes Mellitus, Type 2/physiopathology , Hypoglycemic Agents/administration & dosage , Insulin/administration & dosage , Obesity/drug therapy , Thiazolidinediones/administration & dosage , Blood Glucose/metabolism , Body Composition/physiology , Body Water/physiology , Diabetes Mellitus, Type 2/drug therapy , Female , Fluid Shifts , Humans , Hypoglycemic Agents/pharmacology , Insulin/pharmacology , Male , Middle Aged , Obesity/physiopathology , Pioglitazone , Thiazolidinediones/pharmacology , Treatment Outcome , Water-Electrolyte Balance/drug effects , Water-Electrolyte Balance/physiology
13.
J Med Imaging Radiat Oncol ; 52(6): 583-7, 2008 Dec.
Article in English | MEDLINE | ID: mdl-19178634

ABSTRACT

To determine the overall survival and gastrointestinal toxicity for patients treated with salvage definitive chemo-radiotherapy after primary surgery for locoregional relapse of oesophageal carcinoma. A retrospective review of 525 patients who had a resection for oesophageal or oesophagogastric carcinoma at Princess Alexandra Hospital identified 14 patients treated with salvage definitive radiotherapy or chemo-radiotherapy, following localized recurrence of their disease. We analysed the patient and treatment characteristics to determine the median overall survival as the primary end point. Gastrointestinal toxicity was examined to determine if increased toxicity occurred when the stomach was irradiated within the intrathoracic radiotherapy field. The median overall survival for patients treated with curative intent using salvage definitive chemo-radiotherapy was 16 months and the 2-year overall survival is 21%. One patient is in clinical remission more than 5 years after therapy. Age <60 years old and nodal recurrence were favourable prognostic factors. Treatment compliance was 93% with only one patient unable to complete the intended schedule. Fourteen per cent of patients experienced grade 3 or 4 gastrointestinal toxicity. Salvage definitive chemo-radiotherapy should be considered for good performance status patients with oesophageal carcinoma who have a locoregional relapse after primary surgery. The schedule is tolerable with low toxicity and an acceptable median survival.


Subject(s)
Chemotherapy, Adjuvant/statistics & numerical data , Esophageal Neoplasms/mortality , Esophageal Neoplasms/therapy , Esophagectomy/statistics & numerical data , Neoplasm Recurrence, Local/mortality , Neoplasm Recurrence, Local/therapy , Radiotherapy, Adjuvant/statistics & numerical data , Aged , Humans , Incidence , Middle Aged , Retrospective Studies , Risk Assessment/methods , Risk Factors , Salvage Therapy/statistics & numerical data , Survival Analysis , Survival Rate , Treatment Outcome
14.
J Thromb Haemost ; 4(4): 834-41, 2006 Apr.
Article in English | MEDLINE | ID: mdl-16634754

ABSTRACT

BACKGROUND: Many compounds currently in development for treatment of thrombotic disorders demonstrate high specificity for single targets of blood coagulation such as factor Xa (FXa) or thrombin. AIM: The aim of this study is to determine if inhibition of both FXa and thrombin by simultaneous administration of PD0313052 and argatroban, respectively, synergistically increases the effect of either drug alone in vivo and in vitro. METHODS AND RESULTS: Analyses of thrombin generation from combined inhibition in human plasma using statistical methods of Bliss independence identified a synergistic reduction in thrombin production 30% lower than predicted by simple additivity. The greatest synergy occurred at concentrations of each compound below their individual IC50 values. In a rabbit arterio-venous shunt model (RAV) of thrombosis, co-administration of PD0313052 and argatroban reduced thrombus weight (TW) to a much greater degree than expected by additivity alone producing a synergistic decrease of 45% over the level predicted by additivity. Analyses of thrombin generation in plasma samples from the RAV also demonstrated 38% synergy ex vivo. Furthermore, at plasma concentrations with the greatest synergistic effect, no increase in bleeding or appreciable change in prothrombin time, activated partial thromboplastin time, or activated clotting time was observed, but thrombus weight reduction was greater than twofold higher than that expected from simple additivity. CONCLUSIONS: These results demonstrate a significant synergistic antithrombotic effect of combining low doses of PD0313052 and argatroban and support the hypothesis that simultaneous targeting of multiple coagulation enzymes may offer an improved therapeutic index in the prevention and treatment of thrombosis.


Subject(s)
Factor Xa Inhibitors , Prothrombin/antagonists & inhibitors , Thrombin/metabolism , Thrombosis/drug therapy , Animals , Arginine/analogs & derivatives , Bleeding Time , Fibrinolytic Agents/pharmacology , Humans , In Vitro Techniques , Partial Thromboplastin Time , Pipecolic Acids/pharmacology , Piperidines/pharmacology , Platelet Aggregation Inhibitors/pharmacology , Rabbits , Sulfonamides , Thrombin/chemistry , Thrombosis/diagnosis
15.
J Thromb Haemost ; 3(4): 733-41, 2005 Apr.
Article in English | MEDLINE | ID: mdl-15733062

ABSTRACT

Gas6 (encoded by growth arrest-specific gene 6) is a vitamin-K dependent protein highly homologous to coagulation protein S that is secreted from platelet alpha-granules and has recently been demonstrated to participate in platelet thrombus formation. The current study evaluated the contribution of each of the three known Gas6 receptors (Axl, Sky and Mer) in human and mouse platelet function. Flow cytometry analyses confirmed that all three receptors are present on both human and mouse platelets. Pre-incubation of human platelets with either an anti-Gas6 antibody or blocking antibodies to Sky or Mer inhibited platelet aggregation and degranulation responses to both ADP and the PAR-1 activating peptide, SFLLRN, by more than 80%. In contrast, a stimulatory anti-Axl antibody increased activation responses to these agonists, suggesting a potentiating role for Gas6 in platelet activation. Moreover, in a mouse model of thrombosis, administration of Gas6 or Sky blocking antibodies resulted in a decrease in thrombus weight similar to clopidogrel but, unlike clopidogrel, produced no increase in template bleeding. Thus, Gas6 enhances platelet degranulation and aggregation responses through its known receptors, promoting platelet activation and mediating thrombus formation such that its inhibition prevents thrombosis without increasing bleeding.


Subject(s)
Intercellular Signaling Peptides and Proteins/physiology , Oncogene Proteins/physiology , Platelet Activation , Protein Serine-Threonine Kinases/physiology , Proto-Oncogene Proteins/physiology , Receptor Protein-Tyrosine Kinases/physiology , Thrombosis/metabolism , Ticlopidine/analogs & derivatives , Adenosine Diphosphate/chemistry , Animals , Blood Platelets/cytology , Blood Platelets/metabolism , Clopidogrel , Flow Cytometry , Humans , Mice , Oligopeptides/chemistry , Peptides/chemistry , Platelet Aggregation , Protein Binding , Saccharomyces cerevisiae Proteins , Signal Transduction , Ticlopidine/pharmacology , c-Mer Tyrosine Kinase , Axl Receptor Tyrosine Kinase
16.
Neuroscience ; 116(2): 573-82, 2003.
Article in English | MEDLINE | ID: mdl-12559112

ABSTRACT

Activation of opioid receptors in the CNS evokes a dramatic decrease in heart rate which is mediated by increases in inhibitory parasympathetic activity to the heart. Injection of opiates into the nucleus ambiguus, where premotor cardiac parasympathetic nucleus ambiguus neurons are located elicits an increase in parasympathetic cardiac activity and bradycardia. However, the mechanisms responsible for altering the activity of premotor cardiac parasympathetic nucleus ambiguus neurons is unknown. This study examined at the electron microscopic level whether premotor cardiac parasympathetic nucleus ambiguus neurons possess postsynaptic opioid receptors and whether mu-opioid receptor agonists alter voltage-gated calcium currents in these neurons. Premotor cardiac parasympathetic nucleus ambiguus neurons were identified in the rat using retrograde fluorescent tracers. One series of experiments utilized dual-labeling immunocytochemical methods combined with electron microscopic analysis to determine if premotor cardiac parasympathetic nucleus ambiguus neurons contain mu-opioid receptors. In a second series of experiments whole cell patch clamp methodologies were used to determine whether activation of postsynaptic opioid receptors altered voltage-gated calcium currents in premotor cardiac parasympathetic nucleus ambiguus neurons in brainstem slices. The perikarya and 78% of the dendrites of premotor cardiac parasympathetic nucleus ambiguus neurons contain mu-opioid receptors. Voltage-gated calcium currents in premotor cardiac parasympathetic nucleus ambiguus neurons were comprised nearly entirely of omega-agatoxin-sensitive P/Q-type voltage-gated calcium currents. Activation of mu-opioid receptors inhibited these voltage-gated calcium currents and this inhibition was blocked by pretreatment with pertusis toxin. The mu-opioid receptor agonist endomorphin-1, but not the mu-opioid receptor agonist endomorphin-2, inhibited the calcium currents. In summary, mu-opioid receptors are located postsynaptically on premotor cardiac parasympathetic nucleus ambiguus neurons. The mu-opioid receptor agonist endomorphin1 inhibited the omega-agatoxin-sensitive P/Q-type voltage-gated calcium currents in premotor cardiac vagal nucleus ambiguus neurons. This inhibition is mediated via a G-protein mediated pathway which was blocked by pretreatment with pertusis toxin. It is possible that the inhibition of calcium currents may act to indirectly facilitate the activity of premotor cardiac parasympathetic nucleus ambiguus neurons by disinhibition, such as by a reduction in inhibitory calcium activated potassium currents.


Subject(s)
Analgesics, Opioid/pharmacology , Calcium Channels/physiology , Medulla Oblongata/physiology , Oligopeptides/pharmacology , Parasympathetic Nervous System/physiology , Receptors, Opioid, mu/physiology , Animals , Baroreflex/physiology , Calcium/metabolism , Calcium Channel Blockers/pharmacology , GTP-Binding Proteins/physiology , Heart/innervation , Heart Rate/physiology , Medulla Oblongata/cytology , Medulla Oblongata/drug effects , Microscopy, Electron , Motor Neurons/drug effects , Motor Neurons/physiology , Parasympathetic Nervous System/cytology , Parasympathetic Nervous System/drug effects , Pertussis Toxin/pharmacology , Rats , Rats, Sprague-Dawley , Receptors, Opioid, mu/analysis , Synapses/chemistry , Synapses/physiology , Synapses/ultrastructure , omega-Agatoxin IVA/pharmacology
17.
Clin Ther ; 23(3): 404-12, 2001 Mar.
Article in English | MEDLINE | ID: mdl-11318075

ABSTRACT

BACKGROUND: Many patients with diabetes use mixtures of fast-acting (regular human) insulin and intermediate-acting (neutral protamine Hagedorn [NPH]) insulin to control their blood glucose levels. Premixed insulin is available in a 70%/30% mixture and a 50%/50% mixture of NPH/regular human insulin. For some patients, however, a premixed formulation containing > or =30% regular human insulin can provide too much fast-acting insulin, potentially causing an increased risk for hypoglycemia in the early hours after injection. OBJECTIVE: The pharmacokinetic and pharmacodynamic properties of a premixed formulation of 85% NPH insulin and 15% regular human insulin (85/15) were compared with those of a premixed 70%/30% NPH/regular human insulin preparation and 100% NPH insulin. METHODS: A 12-hour euglycemic clamp approach was used to assess glucose-lowering effects and serum insulin levels in 36 healthy male volunteers in a single-dose (0.5 U/kg), randomized, double-blind, 3-period, crossover study. RESULTS: From 0 to 8 hours after injection, the glucose-lowering effects and serum insulin levels for the 85/15 premixed insulin preparation were significantly greater than those for NPH insulin (P < or = 0.05) but significantly less than those for the 70/30 premixed insulin preparation. The mean (+/- SEM) maximum glucose infusion rate (GIRmax) was 8+/-0.6 mg/(min x kg) for the 85/15 preparation, 7+/-0.6 mg/(min x kg) for NPH, and 9+/-0.6 mg/(min x kg) for the 70/30 preparation, with time to peak GIR (tmax(GIR)) occurring at 313, 360, and 272 minutes, respectively. Time to peak insulin levels did not differ significantly for the 3 preparations, but maximum serum insulin concentration (Cmax(ins)) was significantly different between the groups (70/30 premix: 54+/-2.2 microU/mL; 85/15 premix: 44+/-2.4 microU/mL; NPH: 35+/-1.7 microU/mL). Glucodynamic effect and serum insulin levels did not differ significantly among preparations during the interval from 8 to 12 hours after injection. Mean serum C-peptide levels ranged from -0.6 to 1.0 ng/mL for each preparation during the 12-hour period after injection. CONCLUSIONS: The 85/15 premixed insulin preparation demonstrated clinical pharmacokinetic and pharmacodynamic properties that were intermediate between, and significantly different from, those of NPH insulin and the 70/30 premixed insulin preparation.


Subject(s)
Insulin/pharmacology , Adolescent , Adult , Blood Glucose/analysis , Cross-Over Studies , Double-Blind Method , Humans , Insulin/pharmacokinetics , Male
18.
J Emerg Nurs ; 26(3): 216-22, 2000 Jun.
Article in English | MEDLINE | ID: mdl-10839848

ABSTRACT

INTRODUCTION: Rapid assessment and monitoring is essential for patients with acute bronchospasm. However, tools for measuring dyspnea or the state of being short of breath are often limited to peak flow, blood gas analysis, and asking patients multiple questions about their breathing at a time when they find speaking difficult. We thus decided to examine a tool called the modified Borg scale (MBS) that had the potential to provide quick, easy, and rapid information about a patient's subjective state of dyspnea. This 0 to 10 rated scale gave our ED patients a device they could use to measure and evaluate their dyspnea. For this reason, we added it to the triage assessment practice and included it in all posttreatment assessment notes on patients with exacerbations of asthma or chronic obstructive pulmonary disease (COPD) who were seen in the emergency department and urgent care clinic. STUDY QUESTIONS: (1) Can patients with acute bronchospastic asthma or COPD adequately communicate their level of dyspnea using the MBS? (2) Does subjective improvement in the patient's dyspnea using the MBS correlate with improvements in pulmonary functions as measured by the peak flow meter and cutaneous oxygen saturation (Sao(2))? METHODS: Routine and triage assessment of subjective dyspnea using the MBS was instituted at a hospital emergency department serving adult veterans. Concurrently, the MBS was added to our standardized treatment protocol for management of patients with bronchospasm. ED and urgent care records were reviewed to collect baseline and postrespiratory treatment data on peak expiratory flow rates (PEFR), MBS scores, and Sao(2) percentages. RESULTS: Four hundred male veterans aged 24 to 87 years presented with a chief complaint of dyspnea. The assessing physician identified 102 of these patients as having acute bronchospasm; 42 were diagnosed with asthma, and 60 were diagnosed with COPD. All study patients with acute bronchospasm were able to use the MBS to rate their perception of severity of dyspnea. As the peak flow measurements increased, the MBS scores of difficulty breathing decreased. For the asthma groups, the mean MBS score decreased from 5.1 at triage baseline to 2.4 after treatment. This finding indicated that a significant correlation existed between the change in MBS scores and the change in PEFR from pretreatment to posttreatment scores (r = -.31, P <.05). As the peak flow increased, the MBS scores decreased. Sao(2) only slightly improved in the asthma group compared with the COPD group. For patients with COPD, the mean MBS score decreased from 6.0 at triage baseline to 3.0 after treatment. This finding indicated that a significant correlation also existed between the change in MBS scores and the change in PEFR from pretreatment to posttreatment scores (r = -.42, P <.001). Cutaneous oxygen saturation also improved in the COPD group after treatment. The modality of treatment ordered by the physician was metered dose inhaler or nebulizer. These treatment modalities had no effect on the aforementioned results in the asthma or COPD group. CONCLUSIONS: The MBS is a valid and reliable assessment tool for dyspnea. This study demonstrated that it correlated well with other clinical parameters and could be useful when assessing and monitoring outcomes in patients with acute bronchospasm. Patients who used the MBS rated it with a high degree of satisfaction on ease of use and found that the language in this scale adequately expressed their dyspnea. The ED triage and primary care nursing staff rated the MBS as highly satisfactory, stating that it was quick and easy to use. Respiratory assessment in the triage notes and nursing notes were streamlined to consistently include 3 respiratory measures: PEFR, MBS, and Sao(2). Long respiratory narratives were found to be unnecessary in many cases. In addition, the MBS helped to include an important element of subjective assessment when evaluating the severity of dyspnea.


Subject(s)
Asthma/complications , Dyspnea/diagnosis , Dyspnea/etiology , Lung Diseases, Obstructive/complications , Nursing Assessment/methods , Severity of Illness Index , Adult , Aged , Aged, 80 and over , Blood Gas Analysis , Communication Barriers , Dyspnea/classification , Dyspnea/nursing , Emergency Nursing/methods , Emergency Treatment/methods , Emergency Treatment/nursing , Humans , Male , Middle Aged , Peak Expiratory Flow Rate , Retrospective Studies , Triage/methods
19.
Virus Res ; 55(1): 101-6, 1998 May.
Article in English | MEDLINE | ID: mdl-9712516

ABSTRACT

Two 18-month-old naturally reared ponies were used to investigate the pathogenicity of EHV-2. After dexamethasone treatment, pony 1 was inoculated intranasally with EHV-2 strain T16, which has been isolated from a foal with keratoconjunctivitis superficialis and pony 2 was similarly inoculated with strain LK4 which was originally isolated from a horse with upper respiratory tract disease. Following virus inoculation, pyrexia was not detected in either pony but both developed conjunctivitis, lymphadenopathy, and coughing. EHV-2 was detected in nasal mucus samples up to day 12 post infection (p.i.), in eye swabs up to day 10 p.i., and in buffy coat cells throughout the investigation in both animals. EHV-2-specific antibody titres were raised significantly 18 days p.i. Following the administration of dexamethasone, 3 months p.i., infectious virus was again detected in nasal mucus and conjunctival swabs from both ponies for 7 days. The tissue distribution of EHV-2 genome was studied post mortem, by means of a nested PCR. EHV-2 was detected in lymphoid tissues, lung, conjunctiva, trigeminal ganglia and olfactory lobes of pony 2, whereas in pony 1 only the conjunctiva of the left eye was PCR positive.


Subject(s)
Betaherpesvirinae/pathogenicity , Conjunctivitis, Viral/veterinary , Herpesviridae Infections/veterinary , Horse Diseases/virology , Animals , Antibodies, Viral/blood , Betaherpesvirinae/genetics , Betaherpesvirinae/immunology , Betaherpesvirinae/isolation & purification , Cells, Cultured , Conjunctivitis, Viral/immunology , Conjunctivitis, Viral/virology , DNA, Viral/analysis , Dexamethasone , Eye/virology , Herpesviridae Infections/immunology , Herpesviridae Infections/virology , Horse Diseases/immunology , Horses/virology , Lymphoid Tissue , Nerve Tissue , Nose/virology , Skin , Virus Shedding
20.
Virus Res ; 40(1): 33-45, 1996 Jan.
Article in English | MEDLINE | ID: mdl-8725119

ABSTRACT

The murine intranasal (i.n.) infection model was used to study the molecular distribution of equine herpesvirus-1 (EHV-1) during acute infection, latency and following a reactivation stimulus. After inoculation, infectious virus was detected in lungs, nasal turbinates, brains and olfactory bulbs during the acute phase. A nested PCR (nPCR) readily detected virus in these tissues and, in addition, virus was detected in spleens and (in the second round of nPCR) in peripheral blood mononuclear cells (PBMC). A digoxigenin-labelled in situ hybridization probe detected EHV-1 DNA in bronchiolar and vascular endothelium in the lungs and in and around germinal centres in the spleens. One month later, although infectious virus was absent from all tissues, the trigeminal ganglia, olfactory bulb and PBMC remained positive for virus DNA although this was detected only on the second round of nPCR. Furthermore, in situ hybridization, using either DNA or RNA probes, suggested that little or no transcription of virus occurred in neural tissues during the 'latent phase'. Following a reactivation stimulus, infectious virus was not isolated from any tissues, however, EHV-1 DNA was detected on the first round of nPCR in olfactory bulb, trigeminal ganglia and PBMC. This suggested a quantitative increase in EHV-1 DNA occurred following reactivation stimulus. The significance of these results is discussed in relation to the molecular state of EHV-1 in different tissues at various stages of infection and the validity of the murine model for studying latency and reactivation of EHV-1 in the horses.


Subject(s)
DNA, Viral/analysis , Herpesviridae Infections/virology , Herpesvirus 1, Equid/isolation & purification , RNA, Viral/analysis , Acute Disease , Animals , Cell Line , Disease Models, Animal , Herpesviridae Infections/pathology , Herpesvirus 1, Equid/genetics , Herpesvirus 1, Equid/physiology , Mice , Mice, Inbred BALB C , Rabbits , Virus Latency
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