ABSTRACT
Biomarkers for pulmonary manifestations in systemic lupus erythematosus (SLE) are missing. Plasma samples of nine SLE patients with known pulmonary involvement (SLEpulm) and nine SLE patients without pulmonary involvement (SLE) were tested by multiplex microarray analysis for various cyto- and chemokines. Significantly decreased lung function paramters for forced vital capacity (FVC), total lung capacity (TLC), diffusion capacity for carbon monoxide (DLCO) and diffusion of CO corrected on lung volume (KLCO) were observed in SLEpulm as compared to SLE patients. CC chemokine ligand 21 (CCL21) and interferon gamma-induced protein 10 (IP-10) levels were significantly higher in SLEpulm, than in patients without pulmonary manifestations. CCL21 correlated negatively with DLCO ( r = -0.73; p < 0.01) and KLCO ( r = -0.62; p < 0.01), while IP-10 with FVC and forced expiratory volume one second. Receiver Operating Characteristics (ROC) analysis confirmed high sensitivity and specificity for the separation of SLE patients with and without pulmonary involvement for the chemokines CCL21 (Area Under Curve (AUC): 0.85; sensitivity%: 88.90; specificity%: 75.00; p < 0.01) and IP-10 (AUC: 0.82; sensitivity%: 66.67, specificity%: 100; p < 0.01). Pleuropulmonary manifestations in SLE patients associated with lung functional and DLCO/KLCO changes and were associated with significant increase in CCL21 and IP-10. These chemokines might serve as potential biomarkers of lung involvement in SLE patients.
Subject(s)
Biomarkers/blood , Chemokine CCL2/blood , Chemokine CXCL10/blood , Lung Diseases/immunology , Lupus Erythematosus, Systemic/complications , Adult , Cross-Sectional Studies , Female , Forced Expiratory Volume , Humans , Lung Diseases/physiopathology , Lupus Erythematosus, Systemic/immunology , Lupus Erythematosus, Systemic/physiopathology , Male , Middle Aged , Respiratory Function Tests , Total Lung Capacity , Up-RegulationABSTRACT
Introduction Exhaled carbon monoxide (eCO) has been widely implicated as a pulmonary biomarker in respiratory diseases. The aim of this study was to investigate whether the treatment of patients with severe acute exacerbation of chronic obstructive pulmonary disease (AECOPD) could be aided by monitoring the changes in eCO. Methods The levels of eCO along with routine clinical parameters were analyzed in 29 current smoker and 33 ex-smoker COPD patients, first at the time of hospital admission, and again at discharge following the standard treatment. Patients with AECOPD were also stratified according to sputum bacteria. Results At exacerbation, the levels of eCO were increased in current smokers compared to ex-smokers (6.0 [2.0-9.5] versus 1.0 [1.0-2.0] ppm, p < 0.001). Similarly, eCO levels were higher in smokers after treatment (7.0 [2.0-12.5] versus 1.0 [1.0-2.0] ppm, p < 0.001). Treatment of AECOPD did not affect eCO concentrations. The levels of eCO were not statistically different between bacterial and non-bacterial AECOPD either. Investigating a subgroup of current smoker patients (n = 15), there was a significant correlation between the levels of eCO and blood carboxyhemoglobin concentrations both at exacerbation and discharge. No associations were found between eCO and lung function or blood gas parameters. Conclusion Our results suggest that monitoring eCO during the treatment of AECOPD is of limited clinical value.
Subject(s)
Carbon Monoxide/metabolism , Exhalation/physiology , Monitoring, Physiologic/methods , Pulmonary Disease, Chronic Obstructive/diagnosis , Adult , Aged , Biomarkers/analysis , Biomarkers/metabolism , Breath Tests , Case-Control Studies , Disease Progression , Female , Humans , Male , Middle Aged , Patient Admission , Patient Discharge , Predictive Value of Tests , Pulmonary Disease, Chronic Obstructive/complications , Pulmonary Disease, Chronic Obstructive/metabolism , Smoking/adverse effects , Smoking/metabolism , Smoking Cessation , Sputum/microbiologyABSTRACT
In a recent trial we have assessed fractional exhaled nitric oxide (FENO) in a cohort of patients with an acute exacerbation of chronic obstructive pulmonary disease (COPD). In the current study we have retrospectively investigated the frequency of severe hospitalization-associated exacerbations in the same cohort over 3 years after the initial FENO measurement. A total of 58 COPD patients were enrolled and allocated either into the low (< 27 ppb) or the high (≥ 27 ppb) FENO group depending on their FENO level at exacerbation. Beside the annual rate of exacerbations, sputum culture results and the frequency of antibiotic treatments were also analyzed during the follow-up. Both the number of exacerbations per patient-year and the hospitalization days due to exacerbations were significantly increased in patients from the low FENO group compared to those from the high FENO group. Sputum samples derived from patients in the low FENO group were more frequently indicative of a bacterial infection compared to those obtained from the other subgroup. Also, the frequency of antibiotic treatments was significantly increased in subjects from the low FENO group. Results of this pilot study suggest that COPD patients have diverse risks for future exacerbations depending on their FENO levels at exacerbation.
Subject(s)
Hospitalization/statistics & numerical data , Nitric Oxide/metabolism , Pneumonia, Bacterial , Pulmonary Disease, Chronic Obstructive , Severity of Illness Index , Acute Disease , Aged , Anti-Bacterial Agents/therapeutic use , Breath Tests , Female , Follow-Up Studies , Humans , Male , Middle Aged , Pneumonia, Bacterial/drug therapy , Pneumonia, Bacterial/metabolism , Pneumonia, Bacterial/mortality , Pulmonary Disease, Chronic Obstructive/metabolism , Pulmonary Disease, Chronic Obstructive/microbiology , Pulmonary Disease, Chronic Obstructive/mortality , Retrospective Studies , Sputum/metabolism , Sputum/microbiologySubject(s)
Bronchiolitis Obliterans/diagnosis , Lung Transplantation , Nitric Oxide , Female , Humans , MaleABSTRACT
OBJECTIVES: The effect of hypoxic relapse of chronic obstructive pulmonary disease (COPD) on lung adenosine triphosphate (ATP) concentration was studied measuring ATP in exhaled breath condensate (EBC). SUBJECTS: Thirty COPD patients with severe exacerbation, thirteen healthy non-smokers and thirteen healthy smokers. METHODS: ATP was detected using a luciferin-luciferase assay, dilution of airway droplets in EBC was assessed measuring sample conductivity. RESULTS: ATP concentrations were similar in COPD patients, non-smoking and smoking healthy individuals (141 +/- 44, 115 +/- 21 and 90 +/- 15 pM; p = 0.66). After treatment oxygenation of COPD patients improved (6.85 +/- 1.29 kPa vs. 8.20 +/- 1.28 kPa, p < 0.001), but EBC ATP concentration was similar to that of admission (p = 0.84). There was no correlation between EBC ATP concentration and airway droplet dilution. CONCLUSION: ATP detected in EBC indicates the presence of ATP in airway lining fluid. Lack of difference in ATP concentration between health and COPD suggests that airway ATP level is under complex control of multiple factors.
Subject(s)
Adenosine Triphosphate/metabolism , Breath Tests , Exhalation , Pulmonary Disease, Chronic Obstructive/metabolism , Adult , Aged , Body Fluids/chemistry , Female , Humans , Hypoxia , Male , Middle Aged , Pulmonary Disease, Chronic Obstructive/physiopathology , SmokingSubject(s)
Breath Tests , Humidity , Temperature , Exhalation , Female , Humans , Hydrogen-Ion Concentration , Male , Reference Values , Sampling Studies , Sensitivity and SpecificityABSTRACT
Exhaled breath condensate (EBC) pH is considered to reflect the acid-base balance of the airways. Current pH measurements do not take into account the effect of CO2. The aim of the present study was to determine the effect of condensate CO2 partial pressure on pH and to provide a more precise mode of EBC pH determination. Condensate pH and CO2 partial pressure were measured in parallel from 12 healthy volunteers and 12 asthmatics using a blood gas analyser in neat, argon de-aerated and CO2-loaded samples. The regression analysis was used to test the relationship between pH and CO2, and to calculate the pH at a CO2 level of 5.33 kPa (physiological alveolar CO2 partial pressure). Reproducibility of different pH readings was compared using the Bland-Altman test. Condensate CO2 concentration was variable both in neat and argon de-aerated samples. There was a close negative logarithmic relationship between CO2 and pH. Calculation of pH at a CO2 level of 5.33 kPa provided reproducibility approximately six times as good as that of the currently used measurements. Condensate CO2 partial pressure influences pH measurements. Determination of pH at a standard CO2 level provides the most reproducible condensate pH values to date.
Subject(s)
Acid-Base Equilibrium/physiology , Asthma/physiopathology , Breath Tests , Carbon Dioxide/blood , Adult , Biomarkers/blood , Female , Forced Expiratory Volume/physiology , Humans , Hydrogen-Ion Concentration , Male , Middle Aged , Partial Pressure , Reference Values , Regression Analysis , Reproducibility of Results , Vital Capacity/physiologyABSTRACT
There is an increasing evidence that dietary phytochemicals may play important roles as chemopreventive or chemotherapeutic agents in prevention of many diseases, including tumors. The purpose of this study was to examine antimutagenic effects and effect on the immune response of representative series of substances which commonly occur in human diet. Using the Ames bacterial mutagenicity test and in vivo chemiluminescence test, we investigated antigenotoxic and immunomodulatory effects of juices and vegetable homogenates (carrot + cauliflower, cauliflower, red cabbage, broccoli, onion, garlic) on the genotoxicity of AFB1 and pyrolysates of aminoacids. Using the Ames test and in vivo micronucleus, the chemiluminescence test, the blastic transformation test and the comet assay we examined antimutagenic effects of chemically identified chemoprotective substances in the pure form (resveratrol, diallylsulphide, phenethyl isothiocyanate, ellagic acid, epigallocatechin gallate, genistein and curcumin) on mutagenicity induced by three reference mutagens: aflatoxin B1 (AFB1), 2-amino-3-metylimidazo[4,5,-f] chinolin (IQ) and N-nitroso- N-metylurea (MNU) and effect of phytochemicals on the immunosuppression caused by these mutagens. All complete vegetable homogenates and substances of plant origin tested, showed a clear antimutagenic and immunomodulatory activities on mutagenicity and immunosuppression induced by reference mutagens. Only in the Ames test the effect of some phytochemicals against direct mutagen MNU was lower compared to indirect mutagens AFB1 and IQ. Similarly, resveratrol and epigallocatechin gallate had no inhibitory effect on mutagenicity MNU in the Ames test.
Subject(s)
Antimutagenic Agents/pharmacology , Neoplasms/prevention & control , Nutritional Physiological Phenomena , Vegetables , Animals , Dose-Response Relationship, Drug , Lymphocyte Activation/drug effects , Male , Mice , Mice, Inbred BALB C , Mutagenicity Tests , Mutagens/toxicity , Mutation/drug effects , Neoplasms/immunology , Vegetables/immunologyABSTRACT
OBJECTIVE: Differences between detection techniques may be partly responsible for variable mediator concentrations reported in exhaled breath condensate (EBC). We compared two types of immunoassays to estimate thromboxane A(2) (TxA(2)) concentration. MATERIALS AND METHODS: Thromboxane B(2) (TxB(2)) levels were measured by enzyme immunoassay (EIA) and TxB(2)/2,3-dinor TxB(2) by radioimmunoassay (RIA) in 10 healthy subjects and 13 asthmatic patients. 2,3-Dinor TxB(2) was also determined by a separate EIA. RESULTS: Thromboxane was detected in all samples by RIA, but only in about 75% of samples by EIA. 2,3-Dinor TxB(2) was detected in most samples. There was no agreement between the results of the different immunoassays. As compared to healthy subjects, exhaled breath condensates of asthmatic patients contained significantly more immunoreactivity by RIA and TxB(2) EIA (but not by 2,3-dinor TxB(2) EIA). CONCLUSION: RIA and EIA resulted in vastly different absolute values. The difference found between healthy volunteers and asthmatic patients however, suggests an increased level of TxA(2) in the airways of asthmatics.
Subject(s)
Immunoassay/methods , Thromboxane A2/metabolism , Adult , Aged , Asthma/metabolism , Breath Tests , Bronchi/pathology , Female , Humans , Immunoenzyme Techniques , Male , Middle Aged , Radioimmunoassay , Respiratory Function TestsABSTRACT
We have purified the yeast U5 and U6 pre-mRNA splicing small nuclear ribonucleoproteins (snRNPs) by affinity chromatography and analyzed the associated polypeptides by mass spectrometry. The yeast U5 snRNP is composed of the two variants of U5 snRNA, six U5-specific proteins and the 7 proteins of the canonical Sm core. The U6 snRNP is composed of the U6 snRNA, Prp24, and the 7 Sm-Like (LSM) proteins. Surprisingly, the yeast DEAD-box helicase-like protein Prp28 is stably associated with the U5 snRNP, yet is absent from the purified U4/U6 x U5 snRNP. A novel yeast U5 and four novel yeast U4/U6 x U5 snRNP polypeptides were characterized by genetic and biochemical means to demonstrate their involvement in the pre-mRNA splicing reaction. We also show that, unlike the human tri-snRNP, the yeast tri-snRNP dissociated upon addition of ATP or dATP.
Subject(s)
Fungal Proteins/physiology , RNA Precursors , RNA Splicing , Ribonucleoprotein, U4-U6 Small Nuclear/metabolism , Ribonucleoprotein, U5 Small Nuclear/metabolism , Ribonucleoproteins, Small Nuclear/physiology , Saccharomyces cerevisiae Proteins/physiology , Adenosine Triphosphate/metabolism , Amino Acid Sequence , Animals , Cold Temperature , Deoxyadenine Nucleotides/metabolism , Eukaryotic Cells , Fungal Proteins/genetics , Fungal Proteins/isolation & purification , Fungal Proteins/metabolism , Gene Targeting , Genes, Fungal , Humans , Molecular Sequence Data , Phenotype , Ribonucleoprotein, U4-U6 Small Nuclear/genetics , Ribonucleoprotein, U4-U6 Small Nuclear/isolation & purification , Ribonucleoprotein, U5 Small Nuclear/genetics , Ribonucleoprotein, U5 Small Nuclear/isolation & purification , Ribonucleoproteins, Small Nuclear/genetics , Ribonucleoproteins, Small Nuclear/isolation & purification , Ribonucleoproteins, Small Nuclear/metabolism , Saccharomyces cerevisiae/metabolism , Saccharomyces cerevisiae Proteins/genetics , Saccharomyces cerevisiae Proteins/isolation & purification , Saccharomyces cerevisiae Proteins/metabolism , Sequence Homology, Amino Acid , Zinc FingersABSTRACT
Genotoxic and clastogenic effects of styrene were studied in mice. Male NMRI mice were exposed by inhalation to styrene in concentrations of 750 and 1500 mg/m3 for 21, 7, 3 and 1 days (6 h/day, 7 days/week). Followed parameters included styrene in blood, specific styrene oxide (SO) induced DNA adducts, DNA strand breaks and micronuclei. The formation of SO induced 7-SO-guanines and 1-SO-adenines in DNA was analysed from lung tissues by two versions of the 32P-postlabeling technique. In lungs after 21 days of exposure to 1500 mg/m3 the level of 7-SO-guanine was 23.0+/-11.9 adducts/10(8) normal nucleotides, while 1-SO-adenine was detected at the levels of 0.6+/-0.2 adducts/10(8) normal nucleotides. Both 7-SO-guanines and 1-SO-adenines strongly correlated with exposure parameters, particularly with styrene concentration in blood (r=0.875, P=0.0002 and r=0.793, P=0.002, respectively). DNA breaks were measured in peripheral lymphocytes, bone marrow cells and liver cells using comet assay. To discern oxidative damage and abasic sites, endonuclease III was used. In bone marrow of exposed mice slight increase of strand breaks can be detected after 7 days of inhalation. A significant increase was revealed in the endonuclease III-sensitive sites after 21 days of inhalation in bone marrow. In the liver cells inhalation exposure to both concentrations of styrene did not virtually affect either levels of DNA single-strand breaks or endonuclease III-sensitive sites. The inhalation of 1500 mg/m3 of styrene induced significant increase of micronuclei after 7 days of exposure (10.4+/-2.5/1000 cells, i.e. twice higher micronuclei frequency than in controls). After 21 days of inhalation no significant difference between the control group and the two exposed groups was observed. Whether the decrease of micronuclei after 21 days of inhalation was due to the inhibition of cell proliferation caused by styrene or due to the natural elimination of chromatide fragments, remains to be clarified. An interesting link has been found between DNA single-strand breaks in bone marrow and frequencies of micronuclei (r=0.721, P=0.028).
Subject(s)
DNA Adducts/metabolism , DNA Damage , DNA/drug effects , Micronuclei, Chromosome-Defective , Mutagens/toxicity , Styrene/toxicity , Administration, Inhalation , Animals , Bone Marrow Cells/drug effects , Comet Assay , Dose-Response Relationship, Drug , Epoxy Compounds/metabolism , Erythrocytes/drug effects , Hepatocytes/drug effects , Lung/drug effects , Lung/metabolism , Lymphocytes/drug effects , Male , Mice , Micronuclei, Chromosome-Defective/drug effects , Styrene/administration & dosage , Styrene/pharmacokineticsABSTRACT
Our aim was to study the antioxidant and immunomodulatory effect of silibinin and vitamin E on the early postoperative course in rats that had undergone a partial hepatectomy (PHX). Male Wistar rats that were treated with silibinin (50 mg/b.w.kg i.p.) and/or vitamin E (500 mg/b.w.kg p.o.) were randomised to undergo 70% PHX. At 72 h after operation, Concanavalin A (Con-A) induced lymphocyte proliferation, and lipopolysaccharide (LPS) induced interleukin-1 (IL-1) mitogenicity and tumour necrosis factor-alpha (TNF-alpha) cytotoxicity were measured in the spleen. In addition, total free radical scavenger capacity of the liver was analysed. In PHX animals, Con-A induced lymphocyte proliferation was significantly decreased, and both LPS induced IL-1 and TNF-alpha activity were significantly increased as compared to Sham treated animals. Treatment with silibinin and vitamin E synergistically restored both lymphocyte proliferation (P<0.01) and cytokine activity (P<0.001) in PHX animals. In addition, silibinin and vitamin E synergistically (P<0.001) restored total hepatic free radical scavenger capacity as well as serum levels of AST and gammaGT, that were all markedly decreased in PHX animals. Our results suggest that preoperative treatment with silibinin and/or vitamin E modulates the cellular immunoresponse and restores impaired liver function following PHX, presumably through their antioxidant capacity. This may explain their beneficial effects on the postoperative course of liver repair.
Subject(s)
Antioxidants/pharmacology , Immunity, Cellular/drug effects , Liver/drug effects , Silymarin/pharmacology , Spleen/drug effects , Vitamin E/pharmacology , Animals , Free Radicals/metabolism , Hepatectomy , Liver/enzymology , Liver Function Tests , Male , Rats , Rats, Wistar , Spleen/metabolismABSTRACT
The interaction of amino acids with the herbicide 2,4-dichlorophenoxyacetic acid (2,4-D) was studied by charge-transfer chromatography carried out on diatomaceous layers covered with different amount of 2,4-D and the effect of salts on the strength of interaction was elucidated. It was established that Arg, His, Lys, Orn, Phe and Trp binds to 2,4-D, the binding process is of saturation character. Principal component analysis proved that the concentration of 2,4-D exerts the highest impact on the interaction and the effect of salts is of secondary importance. The results suggest that these amino acid residues may account for the binding of 2,4-D to proteins and can play a considerable role in the detoxification processes by forming conjugates with 2,4-D.
Subject(s)
2,4-Dichlorophenoxyacetic Acid/metabolism , Amino Acids/metabolism , Herbicides/metabolism , Chromatography, Ion Exchange , Chromatography, Thin Layer , Cluster Analysis , Dose-Response Relationship, Drug , Magnesium Chloride/metabolism , Models, Statistical , Models, Theoretical , Potassium Chloride/metabolism , Sodium Chloride/metabolismABSTRACT
Analyzing the results of 99mTc-Technetryle mammascintigraphy in 41 females with breast cancer indicated that polypositional planar mammascintigraphy ensures a high sensitivity (over 88%) in revealing a primary nodule in T1, (more than 95%) in large tumors at above 95% specificity. No nodal accumulation of 99mTc-Technetryle was observed in controls (with fibrocystic mastopathy and suspected coronary heart disease. Mammascintigraphy showed a 85% sensitivity in recognizing axillary lymph nodal metastases too and ascertained that 14 patients had suptaclavicular and subclavian lymph nodal metastases. Therefore, 99mTc-technetryle mammascintigraphy is the method of choice in early detecting a tumorous process, primarily lymphogenic metastasis in breast cancer, and in evaluating its extent.
Subject(s)
Breast Neoplasms/diagnostic imaging , Contrast Media , Technetium Tc 99m Sestamibi , Female , Humans , Lymphatic Metastasis/diagnostic imaging , Posture , Radionuclide Imaging , Sensitivity and SpecificityABSTRACT
The development of the rat submandibular and parotid glands has been studied using antibodies to secretory proteins as cell-specific markers. Although the morphology of the glands and the timing of the main steps of cytodifferentiation are substantially different, they have several proteins and developmental features in common. The latter include the initial formation of perinatal acini which undergo a transition to adult acini expressing a different complement of secretory proteins; the development of adult intercalated ducts (ID) from the perinatal acinar cells; and the retention of the perinatal phenotype in some cells of the ID.
Subject(s)
Parotid Gland/cytology , Parotid Gland/embryology , Submandibular Gland/cytology , Submandibular Gland/embryology , Animals , Biomarkers , Cell Differentiation/physiology , Immunohistochemistry , Parotid Gland/chemistry , Submandibular Gland/chemistryABSTRACT
The human p68, Saccharomyces cerevisiae DBP2 and Schizosaccharomyces pombe dbp2 genes are closely related members of the 'DEAD-box' RNA helicase superfamily. All three genes contain an intron at a conserved site in RNA helicase motif V. The S.cerevisiae intron is unusual both for its position near the 3'-end of the open reading frame and for its size, 1001 nucleotides. We show here that precise deletion of the intron has no effect on cell viability but leads to an increase in Dbp2p protein expression. Inefficient splicing due to the size of the intron can not account for this difference because the intron is efficiently spliced in Dbp2p-deficient cells. Instead, there is a reciprocal relationship between the amount of Dbp2p in the cell and the efficiency with which DBP2 intron-containing genes are expressed. Inactive Dbp2p mutants are efficiently expressed from DBP2 intron-containing plasmids, and fragments of the DBP2 intron confer Dbp2p-responsiveness on heterologous reporter introns. This suggest that there is an intron-mediated negative feedback loop regulating DBP2 expression, and provides a possible explanation for the retention of such an unusual intron in S.cerevisiae.
Subject(s)
Gene Expression Regulation, Fungal/genetics , Homeostasis/genetics , Introns/genetics , RNA Nucleotidyltransferases/genetics , Saccharomyces cerevisiae/genetics , Actins/genetics , Base Sequence , Conserved Sequence/genetics , Feedback , Genes, Fungal/genetics , Humans , RNA Helicases , RNA Nucleotidyltransferases/biosynthesis , RNA Splicing , RNA, Fungal/biosynthesis , RNA, Messenger/biosynthesis , Recombinant Fusion Proteins/biosynthesis , Saccharomyces cerevisiae/enzymology , Sequence DeletionABSTRACT
The influence of partial hepatectomy (PH) on the genotoxic effect of aflatoxin B1 (AFB1) mycotoxin in male Chinese hamsters (Cricetulus griseus) in vivo was studied after a repeated i.p. application of small doses of AFB1 during 8 weeks. The frequency of aberrant cells did not increase after repeated application and persisted throughout the whole period on a relatively stable level. No cumulative genotoxic effect of repeated doses of AFB1 was observed. PH decreased the genotoxic effect of AFB1 only in week 4, while in weeks 6 and 8 no significant differences between hepatectomized and nonhepatectomized animals were recorded.
Subject(s)
Aflatoxin B1/toxicity , Chromosome Aberrations , Hepatectomy , Liver/drug effects , Animals , Cricetinae , Cricetulus , Liver/pathology , MaleABSTRACT
The influence of partial hepatectomy on the genotoxic effect of aflatoxin B1 (AFB1) mycotoxin in male Chinese hamsters (Cricetulus griseus) was studied after application of a single i.p. dose of 1.0 mg AFB1/kg. Changes in the fractions of proliferating bone marrow cells, values of the mitotic index of liver cells and morphologic changes in liver tissue were also monitored. Partial hepatectomy reduced significantly the mutagenic activity of AFB1 measured by the frequency of chromosome aberrations in bone marrow cells during 5 days. In hepatectomized animals AFB1 cytotoxicity was significantly reduced as evaluated by changes in the values of proliferating bone marrow cell fractions. There were no important morphologic changes in the liver. In hepatectomized AFB1 treated animals mitotic activity in liver tissue was substantially lower than in hepatectomized but AFB1 untreated animals.
Subject(s)
Aflatoxins/toxicity , Chromosome Aberrations , Hepatectomy , Aflatoxin B1 , Animals , Bone Marrow/pathology , Bone Marrow/ultrastructure , Cell Division/drug effects , Cricetinae , Cricetulus , Liver/pathology , Liver/ultrastructure , Male , Mitotic IndexABSTRACT
The frequency of chromosomal aberrations in bone marrow cells, after a single i.p. aflatoxin B1 (AFB1) dose, was examined in male Chinese hamsters (Cricetulus griseus). There was a significant increase in aberrant cells within 5 days of administration of a dose of 0.1 micrograms-5 mg AFB1/kg, and on the 36th day. After a single dose of 5 mg AFB1/kg the enhanced frequency of aberrant cells was monitored up to day 104 with no sign of a decrease to control level. The results indicate that the minimum mutagenic effect of an AFB1 dose in this system is 0.1 micrograms/kg. Attention is drawn to the long-term presence of chromosomal aberrations even after a single i.p. exposure to AFB1.
Subject(s)
Aflatoxins/toxicity , Bone Marrow/drug effects , Chromosome Aberrations , Mutagens , Aflatoxin B1 , Aflatoxins/administration & dosage , Animals , Bone Marrow/ultrastructure , Cricetinae , Cricetulus , Dose-Response Relationship, Drug , Injections, Intraperitoneal , Kinetics , MaleABSTRACT
The gene for the U6 small nuclear RNA (snRNA) in the fission yeast Schizosaccharomyces pombe is interrupted by an intron whose structure is similar to those found in messenger RNA precursors (pre-mRNAs) (1). This is the only known example of a split snRNA gene from any organism--animal, plant, or yeast. To address the uniqueness of the S. pombe U6 gene, we have investigated the structures of the U6 genes from five Schizosaccharomyces strains and three other fungi. A fragment of the U6 coding sequence was amplified from the genomic DNA of each strain by the polymerase chain reaction (PCR). The sizes of the PCR products indicated that all of the fission yeast strains possess intron-containing U6 genes; whereas, the U6 genes from the other fungi appeared to be uninterrupted. The sequences of the Schizosaccharomyces U6 gene fragments revealed that each had an intron of approximately 50 base pairs in precisely the same position. In addition to the splice sites and putative branch point regions, a sequence immediately upstream of the branch point consensus was found to be conserved in all of the Schizosaccharomyces U6 genes. This sequence matches the consensus for the B box of eukaryotic tRNA promoters. These results raise the interesting possibility that synthesis of U6 RNA in fission yeast might involve the use of internal promoter elements similar to those found in other genes transcribed by RNA polymerase III.