ABSTRACT
Pirfenidone is an antifibrotic agent for patients with pulmonary fibrosis, but this drug has adverse gastrointestinal (GI) effects. The first aim of this study was to assess GI symptoms due to pirfenidone by using a new questionnaire for reflux symptoms and dismotility symptoms. Whether adding herbal medicine of rikkunshi-to improved GI symptoms due to pirfenidone therapy was also investigated. This was a randomized controlled trial performed on 17 IPF patients. The patients were assigned to two groups, and the study period was 8 weeks. The pirfenidone group received pirfenidone therapy for 8 weeks with add-on rikkunshi-to from 4 weeks, while the control group did not receive either of these agents. To assess the effects of RK, plasma levels of acyl-ghrelin and des-acyl-ghrelin, serum KL-6 and surfactant protein-D, and pulmonary function tests were monitored. GI symptoms were most severe during the initial 2 weeks of pirfenidone therapy at a dose of 600 mg/day. Both reflux symptoms and dismotility symptoms deteriorated. Rikkunshi-to improved GI symptoms to the level prior to pirfenidone therapy. Plasma levels of des-acyl-ghrelin and acyl-/des-acyl-ghrelin ratio changed significantly at 8 weeks compared to 2 weeks. GI adverse events due to PFD were most severe in the first 2 weeks of treatment at a dose of 600 mg/day, and both reflux and dismotility symptoms deteriorated, but the drug was well tolerated at 1200 mg/day. Rikkunshi-to contributed to improvement of GI symptoms, but plasma ghrelin levels did not reflect the improvement of GI symptoms.
Subject(s)
Anti-Inflammatory Agents, Non-Steroidal , Drugs, Chinese Herbal , Gastroesophageal Reflux , Idiopathic Pulmonary Fibrosis/drug therapy , Pyridones , Aged , Aged, 80 and over , Anti-Inflammatory Agents, Non-Steroidal/administration & dosage , Anti-Inflammatory Agents, Non-Steroidal/adverse effects , Drugs, Chinese Herbal/administration & dosage , Drugs, Chinese Herbal/adverse effects , Female , Gastroesophageal Reflux/blood , Gastroesophageal Reflux/chemically induced , Gastroesophageal Reflux/physiopathology , Ghrelin/blood , Humans , Idiopathic Pulmonary Fibrosis/blood , Idiopathic Pulmonary Fibrosis/physiopathology , Male , Middle Aged , Mucin-1/blood , Pyridones/administration & dosage , Pyridones/adverse effects , Surveys and Questionnaires , Time FactorsABSTRACT
Measurement of serum glycopeptidolipid core IgA antibody (GPL antibody) was recently reported to show a high sensitivity and specificity for diagnosing Mycobacterium avium-intracellulare complex (MAC) pulmonary disease (MAC-PD), but its clinical value has not been confirmed. This study aims to evaluate the seropositive rate in patients with suspected MAC-PD based on chest computed tomography (CT), and to examine whether GPL antibody reflects the extent of lung involvement on CT or the number of bacteria in sputum, retrospectively. Among 66 patients with suspected MAC-PD on CT, 36 patients were negative for MAC by culture and 30 were positive. Sputum grades of MAC were evaluated by fluorochrome microscopy of sputum smears. The lungs were divided into six regions to assess the extent of disease. Serum levels of GPL antibody were measured with an enzyme immunoassay (cut-off value >0.7 U/ml). The GPL antibody positive rate was 19.4% among patients who were negative for MAC by culture versus 73.3% among culturepositive patients. The serum level of GPL antibody was significantly correlated with the sputum smear grade (r=0.43, p less than 0.05) and was also correlated with the number of lung regions showing MAC-PD features on CT (r=0.43, less than 0.05). Some MAC-PD patients may have CT features of MAC with positive level of GPL antibody, although the diagnosis cannot be confirmed by culture. GPL antibody levels reflect the pulmonary burden of MAC, as assessed from the sputum smear grade and number of involved regions on chest CT.
Subject(s)
Antibodies, Bacterial/blood , Immunoglobulin A/blood , Mycobacterium avium Complex , Mycobacterium avium-intracellulare Infection , Sputum/microbiology , Tomography, X-Ray Computed , Aged , Aged, 80 and over , Female , Glycolipids/blood , Humans , Lung/diagnostic imaging , Lung/microbiology , Male , Middle Aged , Mycobacterium avium-intracellulare Infection/blood , Mycobacterium avium-intracellulare Infection/diagnosis , Mycobacterium avium-intracellulare Infection/diagnostic imaging , Mycobacterium avium-intracellulare Infection/microbiologyABSTRACT
BACKGROUND: Efficacy of necitumumab [recombinant human monoclonal antibody that blocks the ligand binding epidermal growth factor receptor (EGFR)] in patients with squamous (SQ) non-small-cell lung cancer (NSCLC) has been confirmed in two randomized clinical trials (SQUIRE and JFCM). This study evaluated the association between efficacy and initial skin toxicity with necitumumab treatment by analyzing pooled data from two clinical trials (SQUIRE and JFCM). MATERIALS AND METHODS: Data of 635 patients with SQ-NSCLC (intent-to-treat population) treated with necitumumab plus gemcitabine and cisplatin (N + GC) were pooled from two clinical trials (SQUIRE and JFCM). The relationship between skin toxicities developed by the end of the second cycle and efficacy was evaluated. Efficacy endpoints included overall survival (OS), progression-free survival (PFS), and objective response rate (ORR). Univariate and multivariate analyses were carried out for these endpoints. RESULTS: OS and ORR were associated with skin toxicity, whereas PFS was not. Patients with grade ≥2 or grade 1 skin toxicity had significantly longer OS compared to patients without skin toxicity (grade 0) in the N + GC group [median = 15.0 (grade ≥2); 12.7 (grade 1); 9.4 (grade 0) months; hazard ratio (HR) = 0.51 (grade ≥2 to grade 0); 95% confidence interval (CI) 0.40-0.64, P < 0.001 and HR = 0.64 (grade 1 to grade 0); 95% CI 0.52-0.80, P < 0.001]. In multivariate analysis, OS was significantly associated with skin toxicity. CONCLUSIONS: A significant association was found between necitumumab-induced skin toxicity and efficacy. These results are consistent with the previously reported association between other EGFR inhibitors-induced skin toxicity and efficacy.
Subject(s)
Antibodies, Monoclonal, Humanized , Carcinoma, Non-Small-Cell Lung , Lung Neoplasms , Humans , Carcinoma, Non-Small-Cell Lung/drug therapy , Carcinoma, Non-Small-Cell Lung/pathology , Lung Neoplasms/drug therapy , Lung Neoplasms/pathology , Male , Female , Middle Aged , Aged , Antibodies, Monoclonal, Humanized/therapeutic use , Antibodies, Monoclonal, Humanized/pharmacology , Antibodies, Monoclonal, Humanized/adverse effects , Randomized Controlled Trials as Topic , Adult , Antineoplastic Combined Chemotherapy Protocols/therapeutic use , Antineoplastic Combined Chemotherapy Protocols/pharmacology , Antineoplastic Combined Chemotherapy Protocols/adverse effects , Gemcitabine , Carcinoma, Squamous Cell/drug therapy , Carcinoma, Squamous Cell/pathology , Deoxycytidine/analogs & derivatives , Deoxycytidine/therapeutic use , Cisplatin/therapeutic use , Cisplatin/pharmacology , Cisplatin/adverse effects , Aged, 80 and overABSTRACT
BACKGROUND: We conducted a multicentre feasibility study for single agent long-term S-1 chemotherapy following docetaxel plus cisplatin in patients with curatively resected stage II-IIIA non-small cell lung cancer. METHODS: Patients received three cycles of docetaxel (60 mg m(-2)) plus cisplatin (80 mg m(-2)) and then received S-1 (40 mg m(-2) twice daily) for 14 consecutive days with a 1-week rest for >6 months (maximum, 1 year). The primary end point was feasibility, which was defined as the proportion of patients who completed eight or more cycles of S-1 chemotherapy. If the lower 95% confidence interval (CI) of this proportion was 50% or more, then the treatment was considered as feasible. The sample size was set at 125 patients. RESULTS: One hundred and thirty-one patients were enrolled, of whom 129 patients were eligible and assessable. In all, 109 patients (84.5%) completed 3 cycles of docetaxel plus cisplatin and 66 patients (51.2%, 95% CI: 42.5-59.8) completed 8 or more cycles of S-1 treatment. Grade 3/4 toxicities during the S-1 chemotherapy included anaemia (7.3%), neutropaenia (3.7%), and anorexia (3.7%). CONCLUSION: The toxicity level was acceptable, although the results did not meet our criterion for feasibility. Modification of the treatment schedule for S-1 chemotherapy might improve the treatment compliance.
Subject(s)
Antineoplastic Combined Chemotherapy Protocols/administration & dosage , Carcinoma, Non-Small-Cell Lung/drug therapy , Carcinoma, Non-Small-Cell Lung/surgery , Lung Neoplasms/drug therapy , Lung Neoplasms/surgery , Adult , Aged , Antineoplastic Combined Chemotherapy Protocols/adverse effects , Chemotherapy, Adjuvant , Cisplatin/administration & dosage , Cisplatin/adverse effects , Docetaxel , Drug Administration Schedule , Drug Combinations , Feasibility Studies , Female , Humans , Male , Middle Aged , Oxonic Acid/administration & dosage , Oxonic Acid/adverse effects , Taxoids/administration & dosage , Taxoids/adverse effects , Tegafur/administration & dosage , Tegafur/adverse effects , Young AdultABSTRACT
The insulin receptors from erythrocytes of 50 patients with non-insulin-dependent diabetes mellitus were tested for their ability to autophosphorylate. The assay was performed by a new enzyme-linked immunosorbent assay system that used monoclonal anti-insulin receptor antibodies absorbed to microtiter plates as a first antibody and polyclonal antiphosphotyrosine antibody as a labeled second antibody. By this assay, 3 patients were identified with defects in their insulin receptor kinase, although their defects appeared heterogeneous. Patient 1 had 85% less maximal autophosphorylation with a normal ED50 (1.6 x 10(-9) M insulin). Patient 2, who had polycystic ovary disease, had a 49.2% decrease in maximal autophosphorylation of insulin receptors, and the ED50 was shifted to the right (5.6 x 10(-8) M). Patient 3 with acanthosis nigricans had a normal maximal autophosphorylation, but the ED50 shifted to the right (2.9 x 10(-8) M). The mechanisms for the diversity detected in this assay is not known, but this technique has sufficient specificity and sensitivity to be used to screen for insulin-resistant patients who have a lack of kinase activity.
Subject(s)
Diabetes Mellitus, Type 2/blood , Erythrocytes/metabolism , Insulin Resistance , Receptor, Insulin/analysis , Receptor, Insulin/blood , Adult , Animals , Blood Glucose/metabolism , CHO Cells , Cricetinae , Enzyme-Linked Immunosorbent Assay/methods , Female , Glucose Clamp Technique , Humans , Male , Middle Aged , Phosphorylation , Receptor, Insulin/metabolism , Reference Values , TransfectionABSTRACT
In the present studies, insulin was found to stimulate in a rat hepatoma cell line (called FAO cells) the tyrosine phosphorylation of the 60-kilodalton p21ras GTPase-activating protein (GAP)-associated protein called p60. Surprisingly, the tyrosine phosphorylation of this protein was also almost equally stimulated by an activator of protein kinase C (PKC), the phorbol ester phorbol 12-myristate 13-acetate (PMA). The tyrosine phosphorylation of p60 induced by either agent correlated with the formation of the GAP-p60 complex in situ and an increase in the ability of p60 to directly bind to the SH2 domain of GAP in vitro. Several lines of evidence indicated that the PMA-induced tyrosine phosphorylation of p60 occurred through a different mechanism than that induced by insulin. First, the stimulation of tyrosine phosphorylation of p60 by maximal concentrations of the two agents was almost additive. Second, down-regulation of PKC or pretreatment with a specific inhibitor of PKC abolished the ability of PMA to stimulate tyrosine phosphorylation of p60 but had no effect on the insulin stimulation. And third, long-term pretreatment with insulin abolished the insulin response but did not affect the response to PMA. The PMA effect did seem to be mediated via a tyrosine kinase, since it was blocked by quercetin, an inhibitor of tyrosine kinases. These results indicate that both PMA and insulin can equally stimulate in FAO cells the tyrosine phosphorylation of p60 and its association with GAP, although these two agents seem to act via different signaling systems.
Subject(s)
Liver Neoplasms, Experimental/metabolism , Protein Kinase C/metabolism , Proteins/metabolism , Tetradecanoylphorbol Acetate/pharmacology , Tyrosine/metabolism , Animals , Down-Regulation , GTPase-Activating Proteins , Insulin/pharmacology , Phosphorylation/drug effects , Rats , Receptor, Insulin/metabolism , Second Messenger Systems , Signal Transduction , Tumor Cells, CulturedABSTRACT
A low incidence of lung carcinoma has been reported in cases of prolonged use of aspirin. Cyclooxygenase (COX) 2 expression is frequently seen in adenocarcinoma of the lung, but COX-2 expression in atypical adenomatous hyperplasia (AAH), a possible precursor lesion of adenocarcinoma of the lung, is not known. COX-2 expression was immunohistochemically evaluated in a cohort of 20 cuboidal cell hyperplasias (CCH), 81 atypical adenomatous hyperplasias (AAH), 18 bronchioloalveolar carcinomas (BAC), and 88 invasive adenocarcinomas (I-Ad). The relationship between COX-2 expression and clinicopathologic factors and survival was examined. COX-2 overexpression was detected in over 80% of CCH, AAH, BAC, and I-Ad. However, overexpression was diffuse in AAH (71.6%) and BAC (66.7%). No relationship was found between COX-2 expression and clinicopathological factors or survival. COX-2 expression was most frequently detected in AAH. These findings, taken with previous reports that treatment with COX-2 inhibitor suppresses human colon carcinogenesis, suggest that inhibition of COX-2 may reduce the incidence of human adenocarcinoma of the lung.
Subject(s)
Adenocarcinoma/enzymology , Isoenzymes/biosynthesis , Lung Neoplasms/enzymology , Prostaglandin-Endoperoxide Synthases/biosynthesis , Adenocarcinoma/prevention & control , Aged , Biomarkers, Tumor/biosynthesis , Cyclooxygenase 2 , Female , Humans , Hyperplasia/enzymology , Isoenzymes/antagonists & inhibitors , Lung/enzymology , Lung/pathology , Lung Neoplasms/prevention & control , Male , Membrane Proteins , Middle Aged , Precancerous Conditions/enzymology , PrognosisABSTRACT
Using cDNA array-based gene expression profiling, we previously found reduced expression of the Caspase-5 gene in highly metastatic subpopulations of a lung cancer cell line. The Caspase-5 gene contained poly(A) repeats in its coding region, an area that has been reported to be mutated in both endometrial and gastrointestinal tumors displaying evidence of microsatellite instability. In order to determine the contribution of Caspase-5 gene inactivation to lung cancer development and progression, the mutational status of the Caspase-5 poly(A) tract in 30 primary lung cancers with distant metastasis and 30 lung cancer cell lines was determined by polymerase chain reaction-single strand conformation polymorphism (PCR-SSCP) analysis and direct sequencing. Three somatic mutations of the Caspase-5 gene were found in two out of 30 lung cancer tissues, although no mutations were found in other genes that also contain small nucleotide repeats, such as hMSH3, hMSH6 and BAX. The results of the present study, combined with our prior cDNA array-based gene expression profiling data, suggest that Caspase-5 might be a suppressor gene of highly metastatic potential in lung cancer.
Subject(s)
Caspases/biosynthesis , Caspases/genetics , Lung Neoplasms/genetics , Lung Neoplasms/metabolism , Mutation , Base Sequence , Cell Line, Tumor , DNA Mutational Analysis , DNA, Complementary/metabolism , Disease Progression , Humans , Lung Neoplasms/pathology , Microsatellite Repeats , Molecular Sequence Data , Neoplasm Metastasis , Oligonucleotide Array Sequence Analysis , Poly A , Polymerase Chain Reaction , Polymorphism, Single-Stranded ConformationalABSTRACT
The biosynthesis of 2-deoxystreptamine, the central aglycon of a major group of clinically important aminoglycoside antibiotics, commences with the initial carbocycle formation step from D-glucose-6-phosphate to 2-deoxy-scyllo-inosose. This crucial step is known to be catalyzed by 2-deoxy-scyllo-inosose synthase, which has not yet been characterized so far. Reported in this paper is the first purification of 2-deoxy-scyllo-inosose synthase from butirosin-producing Bacillus circulans SANK 72073 to electrophoretic homogeneity. The enzyme was isolated as a heterodimeric protein comprising from a 23 kDa- and a 42 kDa polypeptide chains. The Km of the enzyme for D-glucose-6-phosphate was estimated to be 9.0 x 10(-4) M and that for NAD+ 1.7 x 10(-4) M, kcat for D-glucose-6-phosphate being 7.3 x 10(-2) s(-1). The presence of Co2+ was essential for the enzyme activity, but Zn2+ was totally inhibitory. While the reaction mechanisms are quite similar, 2-deoxy-scyllo-inosose synthase appears to be distinct from dehydroquinate synthase in the shikimate pathway, with respect to the quaternary structure, metal ion requirement, and the kinetic parameters.
Subject(s)
Anti-Bacterial Agents/biosynthesis , Bacillus/enzymology , Lyases/chemistry , Anti-Bacterial Agents/chemistry , Butirosin Sulfate/biosynthesis , Chromatography, High Pressure Liquid , Cyclization , Electrophoresis, Polyacrylamide Gel , Hexosamines/biosynthesis , Hydrogen-Ion Concentration , Kinetics , Lyases/isolation & purification , Molecular Weight , Spectrophotometry, UltravioletABSTRACT
Many investigators have reported the dose and schedule of VP-16 administration, but as yet they remain undetermined. VP-16 is one of the most active agents for several carcinomas and usually administered intravenously over 3 to 5 consecutive days in combination with other agents. Although, the development of new drugs recently reduces the use of VP-16 administration, VP-16 is still an important drug for the treatment of lung cancer and malignant lymphoma. In this paper, the combination therapy with VP-16, especially in the treatment of lung cancer and malignant lymphoma, are reviewed.
Subject(s)
Antineoplastic Agents, Phytogenic/administration & dosage , Antineoplastic Combined Chemotherapy Protocols/therapeutic use , Carcinoma, Small Cell/drug therapy , Etoposide/administration & dosage , Lung Neoplasms/drug therapy , Lymphoma/drug therapy , Antineoplastic Combined Chemotherapy Protocols/administration & dosage , Carboplatin/administration & dosage , Cisplatin/administration & dosage , Clinical Trials, Phase II as Topic , Cytarabine/administration & dosage , Humans , Ifosfamide/administration & dosage , Mesna/administration & dosage , Methylprednisolone/administration & dosage , Mitoxantrone/administration & dosageABSTRACT
The facial nerve has a specific anatomical feature in that it pursues a relatively long course through a bony canal, originating in the fundus of the internal auditory meatus, until emerging at the stylomastoid foramen. Facial nerve palsy, which is often observed clinically, exhibits a high recovery rate of facial movement. There is no consensus, however, as to the influence of the anatomical features of the facial nerve on the pathological evolution of the palsy. The purpose of this study is to investigate how histological alterations, following injury of the nerve, are influenced by the anatomical feature mentioned above. Mongolian gerbils, weighing 60 g-90 g, were used. Facial nerve palsy was induced by freezing the tympanic part of the facial nerve. Myringotomy was then performed using microscope. The middle ear space was frozen at -2 degrees C to -8 degrees C for 30 seconds through perforation with dimethylether liquid propane gas. Facial nerve palsy was confirmed by loss of the blink reflex and whisker movement. Specimens were removed from the tympanic part of the facial nerve, embedded in epon, and the sections were examined under light and electron microscopy. Out of 16 ears (13 animals) thus frozen, 15 (94%) exhibited complete facial palsy. Facial movement recovered within the 21-to 35-day period after freezing. At thirty-six hours after freezing, thin regenerating axons were seen in Schwann cell basal lamina scaffolds. Even on the seventh day after freezing, when connective tissue around the nerve trunk was thickest, regenerating axons continued to grow and did not degenerate.(ABSTRACT TRUNCATED AT 250 WORDS)
Subject(s)
Facial Nerve/physiology , Facial Paralysis/pathology , Freezing , Nerve Regeneration , Animals , Axons/physiology , Facial Paralysis/physiopathology , GerbillinaeABSTRACT
A 36-year-old male (case-1) and a 54-year-old female (case-2) were admitted to our hospital because of chest oppression on effort. Exercise electrocardiograms of both patients revealed significant ST segment depression in leads II, III, aVF and V5-6. Coronary angiograms demonstrated an anomalous origin of the left circumflex coronary artery in case-1 and an anomalous origin of the right coronary artery in case-2. Furthermore transesophageal echocardiography (TEE) revealed that both anomalous coronary arteries were running from the non-coronary sinus of Valsalva. The anatomical relation between the anomalous coronaries running from non-coronary sinus of valsalva and the great vessels was directly detectable by TEE. Although these cases are very rare, TEE is useful for the assessment of this type of coronary anomaly.
Subject(s)
Coronary Vessel Anomalies/diagnostic imaging , Echocardiography , Sinus of Valsalva/abnormalities , Adult , Female , Humans , Male , Middle AgedSubject(s)
Churg-Strauss Syndrome/diagnosis , Heart Failure/etiology , Kidney Diseases/etiology , Adult , Churg-Strauss Syndrome/complications , Churg-Strauss Syndrome/drug therapy , Colitis/etiology , Female , Humans , Methylprednisolone/administration & dosage , Prednisolone/administration & dosageABSTRACT
A monoclonal antibody to a 60-kDa substrate of the insulin receptor tyrosine kinase is utilized in the present studies to examine this molecule in 3T3 cells expressing either the transforming chicken c-Src (mutant Phe-527), the wild type molecule, or the parental cells. The tyrosine phosphorylation of this 60-kDa protein was greatly increased in cells expressing transforming Src and partially increased in cells expressing wild type enzyme. This tyrosine phosphorylation correlated with an increased association with the GTPase-activating protein of p21ras (GAP). However, this 60-kDa protein did not react with antibodies to another 62-kDa tyrosine-phosphorylated protein previously isolated from Src-transformed cells (Wong, G., Muller, O., Clark, R., Conroy, L., Moran, M. F., Polakis, P., and McCormick, F. (1992) Cell 69, 551-558), although this latter antibody did react with a 62-kDa protein in anti-phosphotyrosine precipitates from cells expressing transforming c-Src but not the parental cells. These two proteins could also be distinguished by their subcellular location, the ability of the latter but not the former protein to bind RNA, and their migration in SDS gels. Moreover, the 62-kDa RNA-binding phosphoprotein could be almost completely depleted from cell lysates with poly(U)-Sepharose without affecting the amount of either the GAP-associated 60-kDa tyrosine-phosphorylated protein or the protein precipitated with the monoclonal antibody. When the two proteins were phosphorylated in vitro with purified c-Src, they were both found to bind directly to the amino-terminal SH2 domain of GAP, although the RNA-binding protein was found to have a weaker affinity. These results indicate that two distinct 60-kDa proteins are substrates for the Src tyrosine kinase, one which binds RNA and the other which constitutes the major GAP-associated 60-kDa phosphoprotein.
Subject(s)
Protein-Tyrosine Kinases/metabolism , Proto-Oncogene Proteins pp60(c-src)/metabolism , 3T3 Cells , Animals , Chickens , GTPase-Activating Proteins , Mice , Phosphoproteins/metabolism , Phosphorylation , Proteins/metabolism , Substrate Specificity , Tyrosine/metabolismABSTRACT
This study was undertaken to evaluate the influence of variations in the vascular pedicle on survival of island flaps. Abdominal island flaps were raised in 128 rats based on the left superficial epigastric vessels. Our results show that stenosis of about one-third of the original external diameter of the artery and vein of the pedicle in our model did not have any significant influence on the survival of the flap and ligation of the femoral artery distal to the branch to the flap did not produce any statistical difference in the viability of the flap.
Subject(s)
Surgical Flaps , Animals , Arteries , Male , Rats , Rats, Inbred Strains , VeinsABSTRACT
Nitrate reduction in roots and shoots and exchange of reduced N between organs were quantitatively estimated in intact 13-d-old seedlings of two-row barley (Hordeum vulgare L. cv. Daisengold) using the (15)N-incorporation model (A. Gojon et al. (1986) Plant Physiol. 82, 254-260), except that NH + (4) was replaced by NO - (2) . N-depleted seedlings were exposed to media containing both nitrate (1.8 mM) and nitrite (0.2 mM) under a light-dark cycle of 12:12 h at 20°C; the media contained different amounts of (15)N labeling. Experiments were started either immediately after the beginning (expt. 1) or immediately prior to the end (expt. 2) of the light period, and plants were sampled subsequently at each light-dark transition throughout 36 h. The plants effectively utilized (15)NO - (3) and accumulated it as reduced (15)N, predominantly in the shoots. Accumulation of reduced (15)N in both experiments was nearly the same at the end of the experiment but the accumulation pattern in roots and shoots during each 12-h period differed greatly depending on time and the light conditions. In expt. 1, the roots accounted for 31% (light), 58% (dark), and 9% (light) of nitrate reduction by the whole plants, while in expt. 2 the contributions of the root were 82% (dark), 20% (light), and 29% (dark), during each of the three 12-h periods. Xylem transport of nitrate drastically decreased in the dark, but that of reduced N rather increased. The downward translocation of reduced (15)N increased while nitrate reduction in the root decreased, whereas upward translocation decreased while nitrate reduction in the shoot increased. We conclude that the cycling of reduced N through the plant is important for N feeding of each organ, and that the transport system of reduced N by way of xylem and phloem, as well as nitrate reduction by root and shoot, can be modulated in response to the relative magnitude of reduced-N demands by the root and shoot, with the one or the other predominating under different circumstances.
ABSTRACT
Stimulation of the activity of protein kinase C by pretreatment of cells with phorbol esters was tested for its ability to inhibit signaling by four members of the insulin receptor family, including the human insulin and insulin-like growth factor-I receptors, the human insulin receptor-related receptor, and the Drosophila insulin receptor. Activation of overexpressed protein kinase C alpha resulted in a subsequent inhibition of the ligand-stimulated increase in antiphosphotyrosine-precipitable phosphatidylinositol 3-kinase mediated by the kinase domains of all four receptors. This inhibition varied from 97% for the insulin receptor-related receptor to 65% for the Drosophila insulin receptor. In addition, the activation of protein kinase C alpha inhibited the in situ ligand-stimulated increase in tyrosine phosphorylation of the GTPase-activating protein-associated p60 protein as well as Shc mediated by these receptors. The mechanism for this inhibition was further studied in the case of the insulin-like growth factor-I receptor. Although the in situ phosphorylation of insulin-receptor substrate-1 and p60 by this receptor was inhibited by prior stimulation of protein kinase C alpha, the in vitro tyrosine phosphorylation of these two substrates by this receptor was not decreased by prior stimulation of the protein kinase C alpha in the cells that served as a source of the substrates. Finally, the insulin-like growth factor-I-stimulated increase in cell proliferation was found to be inhibited by prior activation of protein kinase C alpha.(ABSTRACT TRUNCATED AT 250 WORDS)
Subject(s)
Insulin Resistance , Insulin-Like Growth Factor I/pharmacology , Isoenzymes/metabolism , Phosphoproteins/physiology , Protein Kinase C/metabolism , Receptor, IGF Type 1/physiology , Receptor, Insulin/physiology , Signal Transduction , Amino Acid Sequence , Animals , CHO Cells , Cattle , Cell Division , Cricetinae , Drosophila , Enzyme Activation , GTPase-Activating Proteins , Humans , Insulin Receptor Substrate Proteins , Isoenzymes/biosynthesis , Kinetics , Molecular Sequence Data , Phosphatidylinositol 3-Kinases , Phosphoproteins/biosynthesis , Phosphorylation , Phosphotransferases (Alcohol Group Acceptor)/metabolism , Phosphotyrosine , Protein Kinase C/biosynthesis , Proteins/metabolism , Receptor, IGF Type 1/biosynthesis , Receptor, Insulin/biosynthesis , Recombinant Proteins/biosynthesis , Recombinant Proteins/metabolism , Sequence Homology, Amino Acid , Signal Transduction/drug effects , Tetradecanoylphorbol Acetate/pharmacology , Transfection , Tyrosine/analogs & derivatives , Tyrosine/metabolismABSTRACT
A 60-kDa tyrosine-phosphorylated protein has been observed after insulin treatment of cells in immunoprecipitations of the GTPase-activating protein of Ras (called GAP) as well as the phosphatidylinositol 3-kinase. In the present studies, these two 60-kDa proteins have been shown to differ by limited proteolytic digestions as well as by immunoprecipitation with a monoclonal antibody. This monoclonal antibody was also utilized to show that the 60-kDa GAP-associated protein was rapidly phosphorylated in intact cells after insulin stimulation and to associate with GAP only after insulin treatment of the cells. In addition, the 60-kDa protein was found to be phosphorylated in vitro by the insulin receptor. Finally, the 60-kDa protein immunoprecipitated by this antibody was found not to react with a polyclonal antibody directed against a 62-kDa tyrosine-phosphorylated GAP-associated protein previously observed in src-transformed cells. These studies indicate that insulin stimulates the tyrosine phosphorylation of at least two distinct 60-kDa proteins, one that becomes associated with GAP and appears to be a direct substrate of the insulin receptor kinase and another that associates with the phosphatidylinositol 3-kinase.
Subject(s)
Receptor, Insulin/metabolism , Tyrosine/analogs & derivatives , Animals , Antibodies, Monoclonal , CHO Cells , Cricetinae , Cross Reactions , Electrophoresis, Polyacrylamide Gel , GTPase-Activating Proteins , Humans , Insulin/pharmacology , Kinetics , Molecular Weight , Phosphotyrosine , Proteins/isolation & purification , Proteins/metabolism , Receptor, Insulin/isolation & purification , Substrate Specificity , Transfection , Tyrosine/isolation & purification , Tyrosine/metabolism , ras GTPase-Activating ProteinsABSTRACT
BACKGROUND: Docetaxel, cisplatin and mitomycin C are some of the active drugs used in the treatment of patients with metastatic non-small cell lung cancer (NSCLC). The purpose of this study was to determine the maximum tolerated dose (MTD) and recommended dose of the three drugs in combination for such patients. METHODS: Chemotherapy-native patients with metastatic NSCLC were enrolled in this study. The doses of docetaxel and cisplatin were fixed at 60 and 80 mg/m2, respectively. It was planned to increase the dose of mitomycin C from 4 to 6 and 8 mg/m2. All drugs were administered on day 1 and repeated every 3-4 weeks. RESULTS: All six patients received 60 mg/m2 of docetaxel and 80 mg/m2 of cisplatin, three of them with 4 mg/m2 of mitomycin C (level 1) and the other three with 6 mg/m2 of mitomycin C (level 2). Two of the three level 2 patients experienced dose-limiting toxicities (DLTs) in first cycle: febrile neutropenia and grade 3 hyponatremia. Based on these data, the MTD was concluded to be 60 mg/m2 for docetaxel, 80 mg/m2 for cisplatin and 6 mg/m2 for mitomycin C. Evaluation of the data from all of the cycles, however, showed that four of the six patients experienced DLTs. CONCLUSIONS: The addition of mitomycin C to docetaxel and cisplatin resulted in relatively high toxicities. It was impossible to use a high enough dose of mitomycin C to improve the survival of NSCLC patients. We therefore concluded that further evaluation of this combination is unwarranted.