bluuebunny/crossref_metadata_2025_split huggingface dataset:
Lindane‐induced liver oxidative stress: Respiratory alterations and the effect of desferrioxamine in the isolated perfused rat liver
Authors: Videla Luis A. , Simizu Kiyoko , Barros SilVia B. M. , Junqueira Virginia B. C. 
Published: May 2005

AbstractThe effects of lindane administration (25–60 mg kg−1 for 24 h) on hepatic oxygen consumption were studied in the isolated perfused rat liver, in the absence and presence of the iron‐chelator free‐radical scavenger desferrioxamine. Lindane elicits a dose‐dependent enhancement of total oxygen uptake by the liver, which is largely inhibited by 0·55 mM desferrioxamine. Total desferrioxamine‐ sensitive oxygen consumption exhibits a maximal increase (213 per cent) at 60 mg of lindane kg−1 over control values and represents 21 per cent of the total oxygen consumption. At the different doses of lindane used, it was calculated that about 60 per cent of the total increase in oxygen uptake by the liver is accounted for by oxygen related to oxidative stress, probably utilized at different stages of the induced lipid peroxidative process.
Protection against cadmium toxicity and enzyme inhibition by dithiothreitol
Authors: Ahammadsahib Kabeer I. , Jinna Rajender R. , Desaiah Durisala 
Published: May 2005

AbstractIn the present in vivo studies the alterations in cation transporting enzymes of the brain, kidney and liver tissues were assessed at intervals between 0 to 48 h after a single, acute (10 mg kg−1, i.p.) dose of cadmium (Cd). The inhibition of Na+–K+–ATPase during the first 24 h does not parallel the changes in K+–PNPPase suggesting differential effects on phosphorylation and dephosphorylation steps of the overall ATPase reaction. Between 30 min to 2 h the inhibition in enzyme activity was steep (27 per cent in brain, 54 per cent in liver) followed by a rapid reversal between 2–6 h. This critical period may correspond to the time of induction of metallothionin. This enzyme reversal was followed by a significant decrease in Na+–K+ ATPase (40–68 per cent) and K+‐PNPPase (44–60 per cent) between 24 to 48 h. A similar pattern was observed in Ca2+–ATPase in all the three tissues. A 33 per cent mortality was observed in rats after 48 h of cadmium challenge. Administration of dithiothreitol (DTT, 20 mg kg−1, i.p.) to CdCl2 pretreated rats at 24 h resulted in mortality reduced from 33 per cent to 0 and reversal in the inhibition of Na+‐‐K+–ATPase in brain and kidney and Ca2+–ATPase in brain. Since protection of brain and kidney enzymes by DTT paralleled its protection against Cd toxicity, their inhibition by Cd may, in part, constitute the biochemical basis of Cd toxicity.
Acute phase response to recombinant interleukin‐6 and macrophage‐ and fibroblast‐derived crude cytokine preparations in primary cultures of mouse hepatocytes
Authors: Rokita H. , Mackiewicz M. , Koj A. 
Published: May 2005

AbstractA number of acute phase proteins were determined by electroimmunoassay in media from CBA mouse hepatocytes cultured for 2 days with human recombinant IFN β2/IL‐6, as well as with conditioned media from LPS‐stimulated rat macrophages, and of murine L fibroblasts. It was found that human recombinant IL‐6 caused three‐fold increase in secretion of fibrinogen, while haptoglobin, complement C3 and transferrin were increased respectively, to 168 per cent, 151 per cent, and 145 per cent of the control. DEX(10−7M) in DMEM supplemented with 5 per cent FCS, enhanced the IL‐6 effect on the three positive acute phase proteins. IL‐6 elevated haptoglobin mRNA in mouse hepatocytes to a degree comparable with the concentration of the protein in the culture medium. The effect of conditioned media from murine fibroblasts and peritoneal rat macrophages was generally similar to that of recombinant IL‐6. However, both natural preparations of the cytokines caused decrease in albumin and alpha‐1‐proteinase inhibitor secretion.
A comparison of the effects of various stimulatory agents on t‐PA secretion by normal and malignant cell lines
Authors: Clarke J. , Griffiths B. , Melling J. , Ling R. , Atkinson T. , Electricwala A. 
Published: May 2005

AbstractSuccinyl con A and acetyl con A both stimulated epithelial cells to produce similar yields of tissue plasminogen activator (t‐PA) to those previously obtained with native con A. However, unlike con A, the derivatized lectins did not adversely affect cell morphology and viability, and cells treated with succinyl con A could secrete t‐PA for a prolonged period. Con A and the two derivatives produced similar morphological effects in Bowes melanoma cells, but t‐PA production was not increased. Elevated cyclic nucleotide concentrations did not affect t‐PA production from epithelial cells, but calcium ionophore treatment generated t‐PA yields similar to those obtained with lectins. Azacytidine, which enhanced t‐PA production from epithelial cells, did not increase yields from Bowes melanoma cells, and also sodium butyrate, reported to increase t‐PA yields from human endothelial cells, had no effect on either cell line.
Postnatal changes of cathepsin D activity in rat liver and brain
Authors: Dionyssiou‐Asteriou A. 
Published: May 2005

AbstractTotal and specific activity of cathepsin D (EC. 3.4.23.5) were measured in rat liver and brain from 1 to 98 days of age.The activity of cathepsin D in the liver of adult and newborn rats was the same while in the rat brain it was higher in adult than in newborn rats. In the liver maximum specific activity of cathepsin D occurred on the 10th postnatal day and minimum on the fourth day of age. In the brain maximum specific activity of the enzyme occurred on the 14th postnatal day. Total activity of cathepsin D increased after birth in rat liver and brain. These results are discussed in relation to the functional role of cathepsin D in the rat liver and the brain.
The activation of phosphatidylinositol‐specific phospholipase C by insulin in mammary epithelial cells of lactating mouse
Authors: Yoshimoto Akio , Nakanishi Keiko , Anzai Tadashi , Komine Senichi 
Published: May 2005

AbstractWe have previously demonstrated in vitro that, in the endoplasmic reticulum and Golgi apparatus of mammary epithelial cells of lactating and pregnant mice, inositol 1,4,5‐trisphosphate releases Ca2+ that has been stored in these organelles. In this study, we examined whether insulin and prolactin, essential for the growth of mammary gland and for lactation, influenced the activity of phosphatidylinositol‐specific phospholipase C in mammary cells. In the plasma membrane fraction of mammary epithelial cells of the DDY mouse strain 5 days after the start of lactation after the first pregnancy, and with phosphatidylinostol as substrate, it was shown that the activity of phospholipase C was enhanced by about four times in the presence of insulin compared with the control. Such enhancement was not found in the membrane fraction treated with prolactin.
Acid‐soluble purine and pyrimidine derivatives of growing, encysting and encystment‐inhibited amoebae
Authors: Cumaraswamy Arunthathi , Henney Henry R. 
Published: May 2005

AbstractThe intracellular acid‐soluble purine and pyrimidine derivatives of myxamoebae‐swarm cells of Physarum flavicomum were investigated during growth, microcyst formation, and during adenine‐inhibiton of encystment, using high performance liquid chromatography (HPLC). We also studied the incorporation of exogenous radioactive adenine into the acid soluble purine derivatives and S‐adenosyl‐sulphur compounds separated by HPLC. The most abundant ribonucleoside monophosphate was AMP in the growing and 15 h encysting cells (NC), while it was UMP in the 15 h adenine‐inhibited cells (AIC). ADP was the nucleoside diphosphate present in the greatest quantity in the growing and NC cells but it was CDP in the AIC. The nucleoside triphosphate in highest concentration was ATP, UTP, and GTP in growing, NC, and AIC, respectively. Guanosine was the most abundant nucleoside in all cells. The nucleobase occurring in greatest concentration was cytosine, cytosine and guanine, and adenine in the growing, NC, and AIC, respectively. The AMP content in the 15 h AIC was 2·1‐fold higher than that of adenosine. The 15 h NC had the lowest adenylate energy charge, a value of 0·54 ± 0·02, while the values for growing cells and the AIC were 0·62 ± 0.02 and 0·76 ± 0.01, respectively. [14C]‐Adenine labelling studies (15 h) revealed the occurrence of purine nucleotide interconversion, as the label was detected not only in adenosine, AMP, ADP, ATP, but also in guanine, guanosine, GMP, GDP, GTP, as well as, in inosine monophosphate and xanthosine monophosphate. The percentage incorporation of the radiolabelled adenine into AMP was higher than into adenosine. An increased intracellular level of guanine nucleotides is associated with the inhibition of encystment. The extracellular adenine, rather than internal adenine sources, appears to be the primary precursor of nucleotide for S‐adenosylmethionine synthesis during adenine‐inhibition of encystment.
Amelioration by menadione of the experimental chronic immune arthritis in the rabbit
Authors: Pitsillides A. A. , Blake S. M. , Glynn L. E. , Bitensky Lucille , Chayen J. 
Published: May 2005

AbstractThe immunological induction of arthritis in the knee of the rabbit is well established as a model for human rheumatoid arthritis. It has the special advantage of allowing the development of the condition, and the effect of disease‐modifying agents, to be followed.Attention has been focussed on the activity of glucose 6‐phosphate dehydrogenase in the synovial lining cells since the fourfold elevation of this activity was shown to be fundamental in the human condition. An equal elevation of this activity has now been demonstrated in the rabbit model. Furthermore, it has been shown that the oral administration of menadione decreases this activity towards normality with a concomitant decrease in the degree of inflammation.
Phosphorylation by liver glucokinase of D‐glucose anomers at anomeric equilibrium
Authors: Zähner Dagmar , Malaisse Willy J. 
Published: May 2005

AbstractThe relative contribution of each anomer of D‐glucose to the overall phosphorylation rate of the hexose tested at anomeric equilibrium was examined in rat liver postmicrosomal supernatants under conditions aimed at characterizing the activity of glucokinase, with negligible interference of either hexokinase, N‐acetyl‐D‐glucosamine kinase or glucose‐6‐phosphatase (acting as a phosphotransferase). Both at 10° and 30°C, the relative contribution of each anomer was unaffected by the concentration of D‐glucose. At both temperatures, the α/β ratio for the contribution of each anomer was slightly, but significantly, lower than the α/β ratio of anomer concentrations. These findings, which are consistent with the anomeric specificity of glucokinase in terms of affinity, cooperativity and maximal velocity, reveal that the preferred α‐anomeric substrate for both glycogen synthesis and glycolysis is generated by glucokinase at a lower rate than is β‐D‐glucose‐6‐phosphate.
A 33 kDa protein band in enhanced during long‐term adaptation of EUE cells to a hypertonic medium
Authors: Giuliani Attilia , Ferraretto Anita , Conti Anna Maria Fuhrman , De Grada Laura , Fraschini Annunzia , Pellicciari Carlo , Romanini Maria Gabriella Manfredi 
Published: May 2005

AbstractA cell line derived from human embryonic epithelium (EUE cells) shows an enhanced expression of a 33 kDa protein when adapted to grow in a hypertonic medium containing 0·246 M NaCl (1·8 × the isotonic concentration). The maximum amount of this protein, followed by SDS‐PAGE electrophoresis, was found after 4 days of adaptation; thereafter, the protein band remained fairly constant up to 30 days. When the cells were transferred back to a medium containing 0·137 M NaCl (isotonic medium), the protein pattern reverted to that of control cells. This protein is mainly localized in the cytosol, although a small part is associated with the 150 000 g pellet and needs detergents to be extracted. The molecular weight and the cellular location suggest a possible analogy with the so‐called amphitropic proteins, that are known to interact with both the epidermal growth factor receptor and hydrophobic structures, such as the membrane phospholipids and the cytoskeletal components.
The sensitivity of synthesis of human cartilage matrix to inhibition by IL‐1 suggests a mechanism for the development of osteoarthritis
Authors: Dingle J. T. , Horner A. , Shield M. 
Published: May 2005

AbstractThe damage to articular cartilage, characteristic of arthritic disease, is usually ascribed to increased degradative activity by enzymes or free radicals from locally activated cells.1–3 We propose that inhibition of matrix synthesis, and consequential impairment of the natural repair process, may be at least as important in chronic joint disease.
Cellular thiols in rat liver cell lines possessing different growth characteristics
Authors: Principe Paola , Riley Patrick A. , Slater Trevor F. 
Published: May 2005

AbstractThiol levels were measured in three cell lines derived from rat hepatocytes with different growth rates and degrees of tumorigenicity: IAR20 having normal epithelial morphology and no tumour forming ability: IAR6.1 being a chemically‐transformed malignant cell line; and IAR6.1RT7 derived from an epithelial tumour obtained after injection of IAR6.1 cells into a syngeneic animal. The mean levels of GSH, GSSG, low molecular weight thiols (LMWT), macromolecular thiols (MT) and total reactive protein sulphur (TRPS), expressed as nmoles‐SH mg−1 protein, were found to be 25·5, 7·5, 50·1, 114·5 and 143·6 respectively for IAR20; 37·6, 3·9, 65·4, 126·8 and 148·4 for IAR6.1; 17·2, 4·4, 52·3, 141·0 and 168·2 for IAR6.1RT7.Cultures were treated with D, L‐buthionine‐S, R‐sulphoximine (BSO) to cause greater than 70 per cent depletion of GSH and the measurements of cellular thiols repeated. Although treatment with BSO caused a substantive decrease in the LMWT fraction, there were no major changes in macromolecular thiols or in total reactive protein sulphur. The respective mean values for LMWT, MT and TRPS (expressed as nmoles‐SH mg−1 protein) were 19·4, 109·8, 136·3 for IAR20; 17·2, 119·3, 143·6 for IAR6.1; 21·6, 150·7 and 163·5 for IAR6.1RT7.It is concluded that significant differences in thiol levels exist between the three rat liver cell lines studied. However, severe acute depletion of GSH is not reflected by changes in the levels of macromolecular thiols which suggests that there is only a slow equilibrium between these two major thiol pools.
Cytophotometric assessment of Feulgen‐DNA and coomassie‐total cell protein in adrenocortical fasciculata cells of noise‐exposed wister rats
Authors: Ballough D. U. , Ballough G. P. , Strauss J. A. , Durkot M. J. , Anthony A. 
Published: May 2005

AbstractThe present investigation was undertaken to examine possible noise‐induced alterations in adrenal fasciculata cell (AFC) metabolism, and also to determine if the magnitude of these changes differs in male versus female rats. Wistar rats approximately 3 months old were exposed to intense noise for 60 min (100 dB, re 2 × 10−5 N(m2)−1, 350–20 000 Hz); control rats were house under identical conditions, at an ambient noise level of 40–60 dB. Adrenal fasciculata cells (AFC) from each animal were examined for noise‐induced alterations in Feulgen‐DNA reactivity (as an indicator of chromatin template activity) and Coomassie‐total cell protein levels using scanning‐integrating cytophotometry. The results provide evidence that intense noise elicited a marked AFC metabolic enhancement in both male and female rats; the degree of this enhancement was more pronounced in males. This disparity may be due to pre‐existing differences in male versus female AFC enzymatic capability and subsequent responsiveness to noise‐induced activation.
Effect of vanadate and ouabain on insulin binding and insulin imprinting in Tetrahymena
Authors: Kovács P. , Hegyesi Hargita , Csaba G. 
Published: May 2005

AbstractNa‐metavanadate and ouabain that act on Na+K+‐ATPase had no influence on insulin binding to Tetrahymena immediately after treatment, but after 24 h considerably enhanced the binding capacity of generations of progeny. The increase in binding was of a similar magnitude to that elicited by insulin imprinting. Vanadate failed to increase the imprinting potential of insulin while ouabain even prevented insulin imprinting when administered together with insulin, but, did not affect imprinting when administered after insulin. By analogy with higher organisms it appears that inhibition of Na+K+‐ATPase plays no role in the insulin‐like effect of vanadate on the unicellular Tetrahymena, as judged also from the capacity to bind insulin of the generations of offspring.
Restricted expression of recombination activating gene (RAG‐1) in mouse lymphoid tissues
Authors: Yamamoto Akihito , Atsuta Mitsuru , Hamatani Kiyohiro 
Published: May 2005

AbstractIn an attempt to determine the distribution of recombinase activity in the mouse thymus, spleen and lymph nodes, we used the in situ hybridization method to examine the expression of the recombination activating genes RAG‐1 and RAG‐2. Expression of RAG‐1 was found in most cortical thymocytes but not in the majority of medullary thymocytes. Although hybridization signals of RAG‐2 were not as intense as those of RAG‐1, the localization of RAG‐2 transcripts was similar to that of RAG‐1. In the spleen, expression of RAG‐1 was found only in limited cells near the sinus, and the majority of the cells within the follicle were negative for RAG‐1 transcript. In nude mice, RAG‐1‐expressing cells were detected in the same regions, which suggests that in situ hybridization signals of RAG‐1 in the spleen are due to the cells of B cell origin. In the lymph nodes, expression of RAG‐1 was found only in the medullary region. Expression of RAG‐2 transcript in the spleen and the lymph nodes, if any, was too faint to determine the specific localization. These results suggest that most of the cortical thymocytes and some cells in the spleen are capable of rearranging T cell receptor genes and immunoglobulin genes, respectively, but the possibility of some other explanation could not be ruled out in RAG‐1 expressing cells of the spleen and the lymph nodes.
Brain Na+ K+ ATPase and cholesterol in acute experimental trypanosomiasis
Authors: Nok Andrew J. , Esievo K. A. N. , Ukoha A. I. , Ikediobi C. O. , Ibrahim S. , Martins O. , Tekdek B. , Omage J. 
Published: May 2005

AbstractBrain Na+ K+ ATPase activity has been found to decrease in experimental trypanosomiasis in rats infected with Trypanosoma congolense. Some physical features that affect membrane fluidity were also observed to be altered. The levels of cholesterol in the brain and free fatty acids in the serum were found to increase in the infected animals. These findings might be relevant to the development of brain lesions.
Polymerase chain reaction in the detection of mRNA transcripts from the slow skeletal troponin T (TNNT1) gene in myotonic dystrophy and normal muscle
Authors: Novelli G. , Gennarelli M. , Zelano G. , Sangiuolo F. , Lo Cicero S. , Samson F. , Dallapiccola B. 
Published: May 2005

AbstractRecent studies have shown that the gene encoding for the slow skeletal troponin isoform T (TNNT1) is located on the proximal long arm of human chromosome 19 in the myotonic dystrophy (DM) region. In order to test TNNT1 as a candidate gene for DM, we have isolated TNNT1 cDNA from skeletal muscle from two healthy individuals and from two patients with DM. Sequencing of the TNNT1 cDNA from the DM and normal muscle revealed two sequence variants but no transcriptionally significant mutations. This work rules out a defect in the coding segment of TNNT1 as a cause of DM and provides a polymerase chain reaction protocol for studying troponin T gene expression.
Effect of streptozotocin‐induced diabetes on the handling of phosphate by the rat small intestine
Authors: Al‐Sawan S. , Skillen A. W. 
Published: May 2005

AbstractThe effect of chemically‐induced diabetes on the handling of phosphate (Pi) by rat jejunal enterocytes has been investigated in the presence of a Na‐ or a choline‐gradient. Pi uptake was significantly increased in both gradients. The Pi efflux rate constants for enterocytes from diabetic rats were similar to those of control rats. The effect of diabetes on both the protein and alkaline phosphatase isoenzymes of the rat small intestinal brush‐border membranes was examined using SDS‐PAGE. The patterns given by membranes from rats 14 days after the induction of diabetes were no different from those of controls.
Abnormalities of DNA in human osteoarthritic articular cartilage
Authors: Macha N. , Older J. , Bitensky Lucille , Chayen J. 
Published: May 2005

AbstractThe normal amount of DNA in human diploid nuclei was determined by the use of the Feulgen reaction measured by microdensitometry. The DNA‐content of nuclei in normal human articular cartilage was determined in nuclei of zones 3 and 4 of cartilage of the femoral head removed from osteoporotic fractured necks of femur. Analysis of the results indicated that a degree of synthesis of DNA occurred even in these zones of very elderly persons. Results on these zones in the articular cartilage of osteoarthritic joints indicated that different populations occurred. In some there was DNA‐synthesis related to tetraploidy; in others, the DNA was very stable to acid hydrolysis with no sign of biosynthetic activity; in the last group, which contained erosions of the superficial zones, the DNA was unstable to hydrolysis.
Homologous priming in chemotactic peptide‐stimulated neutrophils
Authors: Bellavite P. , Chirumbolo S. , Lippi G. , Guzzo P. , Santonastaso C. 
Published: May 2005

AbstractThe kinetics and dose‐dependence of activation of human neutrophils exposed to sequential additions of the chemotactic peptide n‐formyl‐methionyl‐leucyl‐phenylalanine (fMLP) have been investigated by multiwell microplate assays. Treatment of neutrophils with medium–high doses (from 10−8 to 5 × 10−7 M) of fMLP caused activation of superoxide anion (O) production, but prevented further activation by a subsequent addition of an optimal dose (from 10−7 M to 5 × 10−7 M) of fMLP. These findings represent an example of cell desensitization, or adaptation. However, neutrophils treated with low, sub‐stimulatory doses (from 10−10 to 5 × 10−9 M) of the peptide and then treated with optimal doses of fMLP exhibited an O production that was two to three‐fold higher than that induced by the same optimal doses on untreated cells. A similar phenomenon of homologous priming of the oxidative metabolism of neutrophil has not previously been described or characterized. Priming was maximal after about 30 min of incubation with fMLP, which differed from desensitization, which required only a few minutes. Homologous priming was not confined to O production, but was also observed with the release of the granule enzyme, lysozyme. Low doses of fMLP were also capable of triggering an increase of intracellular free Ca2+ and of fMLP membrane receptors, which are possible mechanisms responsible for priming.