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Abstract
OBJECTIVES To review the problem of bone metastases and strategies aimed at the management of bone metastases. DATA SOURCES Review articles, book chapters, research studies, and clinical practice. CONCLUSIONS As patients survive for longer periods, effective management of bone metastases becomes critical to maintaining or improving quality of life. Controlling pain, preventing fractures and oncologic emergencies, and promoting mobility and function are the outcomes of successful management. IMPLICATIONS FOR NURSING PRACTICE Use of a clinical algorithm may assist the nurse in identifying bone metastases and managing the clinical sequelae, such as pain.
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Xu M, Bastos J, Dmitrewski J, Okajima H, Gunson B, Pirenne J, Buckels J, McMaster P, Mayer D. Perihepatic packing in liver transplantation. Transplant Proc 1998; 30:1850-1. [PMID: 9723305 DOI: 10.1016/s0041-1345(98)00454-0] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/08/2023]
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Mayer D. Guidelines for care of the elderly. Ann Emerg Med 1998; 32:115; author reply 116. [PMID: 9656964] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [MESH Headings] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/08/2023]
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von Tirpitz C, Glasbrenner B, Mayer D, Malfertheiner P, Adler G. Comparison of different endocrine stimulation tests in nondiabetic patients with chronic pancreatitis. HEPATO-GASTROENTEROLOGY 1998; 45:1111-6. [PMID: 9756016] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Subscribe] [Scholar Register] [Indexed: 02/08/2023]
Abstract
BACKGROUND/AIMS The purpose of this study was to evaluate endocrine functional impairment in nondiabetic patients with chronic pancreatitis and to determine its reliability in the staging of this disease. METHODOLOGY Eighteen patients with chronic pancreatitis and fasting normoglycemia (fasting blood glucose level < 100 mg/dl) and 10 healthy subjects underwent an oral glucose tolerance test (OGTT), an intravenous glucose test (IGT) and an arginine stimulation test (AST). Blood glucose and serum concentrations of insulin, C-peptide and glucagon were measured before and after stimulation. Exocrine pancreatic function was assessed by the pancreolauryl serum test (PLT), and morphological changes were staged by endoscopic retrograde pancreaticography (ERP), which were rated as I (mild), II (moderate) or III (severe). RESULTS Glucagon and C-peptide secretions after arginine stimulation were reduced in patients with moderate and severe chronic pancreatitis while no parameter was able to show impaired endocrine function in the early stage (ERP I) of the disease. Serum insulin concentrations proved to be of no use in the diagnosis of pathological B-cell function, since even patients with severe chronic pancreatitis and fasting normoglycemia demonstrated normal insulin secretion. CONCLUSIONS We conclude that there is a close correlation between morphological changes of the pancreas and functional endocrine reserve capacity, whereas endocrine stimulation tests were not shown to be helpful in the clinical assessment of nondiabetic patients with chronic pancreatitis.
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Mayer D, Metzger C, Leonetti P, Beier K, Benner A, Bannasch P. Differential expression of key enzymes of energy metabolism in preneoplastic and neoplastic rat liver lesions induced by N-nitrosomorpholine and dehydroepiandrosterone. Int J Cancer 1998; 79:232-40. [PMID: 9645343 DOI: 10.1002/(sici)1097-0215(19980619)79:3<232::aid-ijc4>3.0.co;2-q] [Citation(s) in RCA: 20] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/08/2022]
Abstract
Preneoplastic liver foci and neoplasms of different morphological phenotypes were induced in rats with N-nitrosomorpholine (NNM; 120 mg/l in drinking water for 7 weeks) and the peroxisome proliferator dehydroepiandrosterone (DHEA; 0.6% in the diet for up to 84 weeks). Preneoplastic glycogen storage foci (GSF) occurred mainly upon treatment with NNM, and amphophilic cell foci (APF) were mainly observed in rats treated with DHEA alone or in combination with NNM. The 2 types of lesions belong to 2 different cellular lineages, the glycogenotic/basophilic lineage and the amphophilic lineage, which are characterized by distinct patterns of alterations in key enzymes of energy metabolism. Whereas in GSF enzymes of glucose metabolizing pathways were modified (increase in glucose-6-phosphate dehydrogenase and pyruvate kinase, decrease in glucose-6-phosphatase), APF mainly demonstrated alterations in mitochondrial enzymes (increase in cytochrome c oxidase, succinate dehydrogenase and glycerol-3-phosphate dehydrogenase) and, to a lower extent, in peroxisomal enzymes (increase in peroxisomal hydratase and acyl-CoA oxidase). The alterations in enzyme expression reflect an insulinomimetic effect in GSF and a thyromimetic effect in APF. Neoplasms resulting from APF show a more differentiated phenotype than those arising from GSF. We suggest that the different and in many aspects opposite effects of the 2 carcinogens on key enzymes of distinct pathways of energy metabolism modulate the process of neoplastic liver cell transformation and result in phenotypically different preneoplasias and neoplasias reflecting different cellular lineages.
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Stauch S, Kircheis G, Adler G, Beckh K, Ditschuneit H, Görtelmeyer R, Hendricks R, Heuser A, Karoff C, Malfertheiner P, Mayer D, Rösch W, Steffens J. Oral L-ornithine-L-aspartate therapy of chronic hepatic encephalopathy: results of a placebo-controlled double-blind study. J Hepatol 1998; 28:856-64. [PMID: 9625322 DOI: 10.1016/s0168-8278(98)80237-7] [Citation(s) in RCA: 99] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 12/13/2022]
Abstract
BACKGROUND/AIMS In the current state of knowledge of the pathophysiology of hepatic encephalopathy, a reduction in hyperammonemia is the most important evidence of effective treatment. Therefore, the therapeutic efficacy of oral L-ornithine-L-aspartate, which improves impaired ammonia detoxification, was investigated in patients with cirrhosis, hyperammonemia and stable, overt, chronic hepatic encephalopathy, and in subclinical hepatic encephalopathy in a randomized, double-blind, placebo-controlled clinical trial. METHODS Oral L-ornithine-L-aspartate was administered three times daily at fixed times for 14 consecutive days in a total dose of 18 g per day. The design was chosen to prevent an increase in ammonia induced by a protein meal of 0.25 g/kg body weight, given at the start of the daily treatment period. Efficacy variables were: fasting and postprandial ammonia concentration, Number-Connection-Test time, mental state grades, and a Portosystemic Encephalopathy Index. Analyses were based on the total study sample of 32 placebo- and 34 L-ornithine-L-aspartate-treated patients as well as on the subgroup samples in the overt (20 placebo- and 23 L-ornithine-L-aspartate-treated) and subclinical hepatic encephalopathy (12 placebo- and 11 L-ornithine-L-aspartate-treated) patients. RESULTS Number Connection Test performance times (p<0.01) as well as fasting (p<0.01) and postprandial (p<0.05) venous blood ammonia concentrations in the L-ornithine-L-aspartate-treated group showed improvement in comparison to placebo. Also, the mental state grade (p<0.05) and the Portosystemic Encephalopathy Index (p<0.01), improved to a much greater degree in the L-ornithine-L-aspartate group than in the placebo group. Adverse events were observed in neither the placebo nor the L-ornithine-L-aspartate-treated patients. CONCLUSION Oral L-ornithine-L-aspartate is a safe, well-tolerated treatment with a good compliance rate and a beneficial therapeutic effect in patients with cirrhosis and stable, overt, chronic hepatic encephalopathy.
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Thomson M, McKiernan P, Buckels J, Mayer D, Kelly D. Generalised mitochondrial cytopathy is an absolute contraindication to orthotopic liver transplant in childhood. J Pediatr Gastroenterol Nutr 1998; 26:478-81. [PMID: 9552151 DOI: 10.1097/00005176-199804000-00024] [Citation(s) in RCA: 54] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 02/07/2023]
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Jonsson NN, Daniel RC, Mayer D, Verrall R. Effects of oral dosing with calcium propionate on total calcium and glucose concentrations in the plasma of the cow. ZENTRALBLATT FUR VETERINARMEDIZIN. REIHE A 1998; 45:127-36. [PMID: 9673568 DOI: 10.1111/j.1439-0442.1998.tb00808.x] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
Abstract
This study aimed to determine the effect of oral drenching with molasses, calcium propionate and MgO on plasma glucose and calcium concentrations of dairy cows. Four trials were undertaken, each using three lactating and three non-lactating Jersey cows. In Trial 1, the effect of drenching with 200 ml molasses was measured. Trial 2 measured the effect of a single treatment with 349 g calcium propionate in 200 ml molasses. In Trial 3, the effect of 60 g MgO in molasses alone and in combination with calcium propionate was measured. Trial 4 tested the effect of repeating treatments with 349 g calcium propionate in 200 ml molasses 24 h apart. Dosing with 349 g calcium propionate in molasses increased plasma total calcium (Catot) concentration by 10% in lactating and non-lactating cows for periods less than 7 h, and this was not augmented by simultaneous administration of MgO or treatment 24 h earlier with 349 g calcium propionate in molasses. Treatment with 200 ml molasses alone resulted in increased plasma Catot of 7%. Plasma glucose concentrations were elevated by 11% for less than 3 h after treatment with calcium propionate. For the prevention of subclinical hypocalcaemia and ketosis in early lactation, drenching with calcium propionate solutions is unlikely to be of value due to the short duration of its effects, but the inclusion of calcium propionate in the postpartum ration deserves further investigation.
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Mayer D, Klimek F, Bannasch P. Cytochemical and biochemical studies on adenylate cyclase activity in preneoplastic and neoplastic liver tissue and cultured liver cells. Microsc Res Tech 1998; 40:463-72. [PMID: 9551627 DOI: 10.1002/(sici)1097-0029(19980301)40:6<463::aid-jemt6>3.0.co;2-q] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/16/2022]
Abstract
The ATP-analogue adenylyl(beta,gamma-methylene)diphosphonate was chosen as substrate for the cytochemical localization of adenylate cyclase (AC) activity. The tissues investigated covered normal rat liver and liver from carcinogen-treated animals with preneoplastic lesions and hepatocellular neoplasms, as well as cultured liver cells. The AC reaction product methylene diphosphonate was precipitated with Pb2+ immediately at the place of production. This approach permitted a precise localization of AC activity by light and electron microscopy. The specificity of the AC reaction was demonstrated by control reactions, including inhibition of AC with 2'5'-dideoxyadenosine and activation with forskolin, glucagon, and cholera toxin. Endogenous phosphatases were inhibited with tetramisole and NAD. In normal liver, AC activity was mainly localized in the sinusoidal membrane of hepatocytes. A distinct gradient in activity was observed within the liver lobule. Hepatocytes localized around the terminal hepatic venule showed a significant higher AC activity compared to hepatocytes near the portal tract. AC was clearly decreased in focal preneoplastic liver lesions of the glycogenotic-basophilic cell lineage leading to hepatocellular carcinomas. Cytochemically detected intensity of AC activity corresponded to data obtained by microbiochemical assays in laser-dissected tissue samples. A remarkable interdependence of AC activity and degree of differentiation was also seen in epithelial rat liver cell lines: Highly differentiated cells show high enzyme activity and vice versa, as shown by both cytochemical and biochemical examinations. It is concluded that alterations in cellular signal transduction caused by alterations in AC activity play an important role in hepatocarcinogenesis.
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Mayer D, Forstner K, Beier K, Völkl A. Monoclonal antibodies against proliferating cell nuclear antigen cross-react with the peroxisomal multifunctional protein. Anal Biochem 1998; 256:135-7. [PMID: 9466809 DOI: 10.1006/abio.1997.2485] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.0] [Reference Citation Analysis] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/06/2023]
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Abstract
STUDY OBJECTIVE To analyze the effects of epidural analgesia for labor when dystocia occurs. DESIGN Retrospective cohort study. SETTING Academic health center. PATIENTS 641 low risk, nulliparous women in spontaneous labor. INTERVENTIONS 406 (63%) women received epidurals analgesia and 253 (37%) did not. Sixty women (9.4%) required an abdominal delivery for dystocia. MEASUREMENTS AND MAIN RESULTS Women receiving epidural analgesia were more likely to be white, receive care from an attending physician, need labor augmentation, and deliver a heavier infant. Multivariate analysis identified five variables predictive of dystocia and abdominal delivery: pitocin augmentation odds ratio (O.R.) = 3.9 (2.0 to 7.6), duration of labor more than 20 hours O.R. = 2.4 (1.3 to 4.4), high epidural dose O.R. = 2.2 (1.2 to 4.1), birthweight over 4,000 grams O.R. = 2.0 (1.0 to 4.2), and early placement of epidural O.R. = 1. 9 (1.0 to 3.5). Repeating the regression after excluding the 20 women who developed abnormal labor prior to epidural placement (18 of 20 women had protracted dilatation) demonstrated that pitocin augmentation O.R. = 4.0 (1.8 to 4.), high epidural dose O.R. = 3.0 (1.9 to 6.2), duration of labor greater than 20 hours O.R. = 2.7 (1.3 to 5.7), and birthweight over 4,000 grams O.R. = 2.1 (0. 9 to 4.8) were associated with dystocia. CONCLUSION Epidural analgesia appears to be a marker of abnormal labor rather than a cause of dystocia. High concentration anesthetics and epinephrine should be avoided, as they may influence labor. Randomized, controlled trials of this technique will be difficult to do; our work should reassure patients and their clinicians that epidural analgesia does not adversely affect labor.
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Ploner O, Mayer D, Ziegler B, Hehrmann R. Diagnostic and therapeutic confusion caused by TBG deficiency in an 18 years old adolescent. Exp Clin Endocrinol Diabetes 1998; 105 Suppl 4:79. [PMID: 9439924 DOI: 10.1055/s-0029-1211941] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 02/05/2023]
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Mayer D, Miller-Hänisch B, Böckh A, Hehrmann R. Fulminant meningococcal meningitis and sepsis associated with severe hypothyroidism caused by autoimmune (Hashimoto) thyreoiditis. Exp Clin Endocrinol Diabetes 1998; 105 Suppl 4:80. [PMID: 9439925 DOI: 10.1055/s-0029-1211942] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 02/05/2023]
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Metzger C, Bannasch P, Mayer D. Enhancement and phenotypic modulation of N-nitrosomorpholine-induced hepatocarcinogenesis by dehydroepiandrosterone. Cancer Lett 1997; 121:125-31. [PMID: 9570349 DOI: 10.1016/s0304-3835(97)00341-8] [Citation(s) in RCA: 10] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/07/2023]
Abstract
Hepatocarcinogenesis was induced in male and female rats by continuous administration of the adrenal steroid dehydroepiandrosterone (DHEA; 0.6% in the diet) with and without previous treatment with N-nitrosomorpholine (NNM; 120 mg/l drinking water for 7 weeks). DHEA treatment alone resulted in hepatocellular adenomas (HCA) and carcinomas (HCC) after 72-84 weeks, the incidence of both benign and malignant neoplasms being higher in females than in males. After DHEA administration for up to 32 weeks subsequent to NNM, the incidence of HCA and HCC was significantly higher (HCA, 42%; HCC, 42%) than after NNM alone (HCA, 33%; HCC, 28%). While total tumor incidence was similar in male (63%) and female (60%) rats after NNM treatment alone, it was higher in females (87%) than in males (80%) after NNM/DHEA treatment. The difference between the genders was mainly due to the higher incidence of HCC in females. Morphometric analysis of preneoplastic foci of altered hepatocytes (FAH) yielded that DHEA treatment did not increase the average total number of FAH induced by NNM, but caused a modulation of the phenotype of FAH from the glycogenotic/basophilic to the amphophilic cell lineage. The results confirm that DHEA acts as a hepatocarcinogen and show for the first time that it enhances NNM-induced hepatocarcinogenesis in rats.
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Langer K, Mutschler E, Lambrecht G, Mayer D, Troschau G, Stieneker F, Kreuter J. Methylmethacrylate sulfopropylmethacrylate copolymer nanoparticles for drug delivery. Int J Pharm 1997. [DOI: 10.1016/s0378-5173(97)00255-x] [Citation(s) in RCA: 12] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/18/2022]
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Zoepf T, Mayer D, Merckle E, Adler G, Beckh K. Portal vein thrombosis and multiple liver abscesses in Crohn's disease--an example for successful conservative treatment. ZEITSCHRIFT FUR GASTROENTEROLOGIE 1997; 35:627-30. [PMID: 9297777] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Subscribe] [Scholar Register] [Indexed: 02/05/2023]
Abstract
We report about a 27-year-old patient with Crohn's disease presenting with two complications; Portal vein thrombosis and multiple liver abscesses. Conservative treatment with antibiotics and percutaneous catheter drainage was successful, the liver abscesses disappeared. 18 months later the patient presented in best condition. Ultrasound showed cavernous transformation of the portal vein system and splenomegaly, discrete esophageal varices were seen by esophagogastroscopy. This is an example for an excellent course under conservative therapy of liver abscesses, on the other hand it is the first reported case of a patient with a combination of portal vein thrombosis and multiple liver abscesses in Crohn's disease.
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Bannasch P, Klimek F, Mayer D. Early bioenergetic changes in hepatocarcinogenesis: preneoplastic phenotypes mimic responses to insulin and thyroid hormone. J Bioenerg Biomembr 1997; 29:303-13. [PMID: 9387091 DOI: 10.1023/a:1022438528634] [Citation(s) in RCA: 48] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/05/2023]
Abstract
Biochemical and molecular biological approaches in situ have provided compelling evidence for early bioenergetic changes in hepatocarcinogenesis. Hepatocellular neoplasms regularly develop from preneoplastic foci of altered hepatocytes, irrespective of whether they are caused by chemicals, radiation, viruses, or transgenic oncogenes. Two striking early metabolic aberrations were discovered: (1) a focal excessive storage of glycogen (glycogenosis) leading via various intermediate stages to neoplasms, the malignant phenotype of which is poor in glycogen but rich in ribosomes (basophilic), and (2) an accumulation of mitochondria in so-called oncocytes and amphophilic cells, giving rise to well-differentiated neoplasms. The metabolic pattern of human and experimentally induced focal hepatic glycogenosis mimics the phenotype of hepatocytes exposed to insulin. The conversion of the highly differentiated glycogenotic hepatocytes to the poorly differentiated cancer cells is usually associated with a reduction in gluconeogenesis, an activation of the pentose phosphate pathway and glycolysis, and an ever increasing cell proliferation. The metabolic pattern of preneoplastic amphophilic cell populations has only been studied to a limited extent. The few available data suggest that thyromimetic effects of peroxisomal proliferators and hepadnaviral infection may be responsible for the emergence of the amphophilic cell lineage of hepatocarcinogenesis. The actions of both insulin and thyroid hormone are mediated by intracellular signal transduction. It is, thus, conceivable that the early changes in energy metabolism during hepatocarcinogenesis are the consequence of alterations in the complex network of signal transduction pathways, which may be caused by genetic as well as epigenetic primary lesions, and elicit adaptive metabolic changes eventually resulting in the malignant neoplastic phenotype.
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Klatt S, Taut C, Mayer D, Adler G, Beckh K. Evaluation of the 13C-methacetin breath test for quantitative liver function testing. ZEITSCHRIFT FUR GASTROENTEROLOGIE 1997; 35:609-14. [PMID: 9297776] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Subscribe] [Scholar Register] [Indexed: 02/05/2023]
Abstract
Noninvasive 13C-breath tests are used for the assessment of hepatocellular dysfunction. 13C-methacetin is metabolized in the liver by O-demethylation to 13CO2 and acetaminophen. The aim of the study was to evaluate the 13C-methacetin breath test in comparison to the Child-Pugh score and other quantitative liver function tests (MEGX-test and indocyanin green-clearance). 2 mg/kg 13C-methacetin were orally given to 31 patients with histologically proven liver cirrhosis of different etiology and severity (nine Child A, 13 Child B, nine Child C), ten patients with chronic viral hepatitis and ten healthy volunteers. The increase of exhaled 13CO2 was expressed as delta over baseline (DOB; delta /1000). Different DOB-values were compared as parameters for assessing hepatocellular dysfunction. All breath test parameters analyzed provided an excellent discrimination between cirrhotic and noncirrhotic individuals. The DOB-value at 20 min showed a superior correlation with the Child-Pugh score (r = 0.67) than did MEGX-test or indocyanine green clearance results (r = 0.39 and r = 0.43, respectively). With a cut-off value of < or = 25 delta /1000 at 20 min, sensitivity and specificity to discriminate between cirrhotic and noncirrhotic individuals was 93.5% and 95%, respectively. The 13C-methacetin breath test is a safe and precise quantitative liver function test. Using one single breath sample 20 min after substrate administration, the test discriminates well between cirrhotic and noncirrhotic patients. Its prognostic value remains to be established.
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Beier K, Völkl A, Metzger C, Mayer D, Bannasch P, Fahimi HD. Hepatic zonation of the induction of cytochrome P450 IVA, peroxisomal lipid beta-oxidation enzymes and peroxisome proliferation in rats treated with dehydroepiandrosterone (DHEA). Evidence of distinct zonal and sex-specific differences. Carcinogenesis 1997; 18:1491-8. [PMID: 9276621 DOI: 10.1093/carcin/18.8.1491] [Citation(s) in RCA: 25] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/05/2023] Open
Abstract
Dehydroepiandrosterone (DHEA) is an intermediate product in the synthesis of male and female sex hormones in the adrenal cortex of man. In livers of rats and mice DHEA increases the levels of cytochrome P450 IVA and peroxisomal beta-oxidation enzymes associated with peroxisome proliferation. Prolonged treatment of rats with DHEA induces liver tumors that are more frequent in females arising mainly in the periportal regions of the liver lobule (Metzger et al., Toxicol. Pathol. 23, 591-605, 1995). Because of paucity of information on hepatic zonation of peroxisomal response to DHEA and controversial reports on gender-specific differences of its effects the present study was undertaken using qualitative immunohistochemical and quantitative immunoelectron microscopical techniques in addition to Western blotting. Rats were treated for 24 weeks with 0.6% DHEA supplied with diet. Immunoblot analysis revealed marked induction of peroxisomal beta-oxidation enzymes, which by quantitative analysis was equally strong in male and female animals, whilst catalase and urate-oxidase were not increased. Cytochrome P450 IVA, in contrast, was induced significantly stronger in male than in female rats. Immunohistochemistry confirmed the induction of cytochrome P450 IVA showing a marked lobular gradient in female animals with strong induction in pericentral and almost no induction in periportal regions of the liver lobule. In male animals cytochrome P450 IVA was expressed more uniformly across the liver lobule. A similar sex specific zone-dependent response was observed for peroxisomes. DHEA induced in females a significant zonal gradient with marked peroxisome proliferation and a strong induction of peroxisomal hydratase/dehydrogenase in pericentral hepatocytes and a much smaller response in periportal regions. Livers of male animals, in contrast, showed a uniform peroxisomal proliferation to DHEA with only slight zonal differences. The striking homologies of the induction patterns of cytochrome P450 IVA and the peroxisome proliferation in both sexes support the notion of a functional relationship. In view of the almost exclusive periportal localization of DHEA-induced tumors in female rats in contrast to the pericentral localization of the peroxisomal proliferation shown by this study, it seems likely that other factors in addition to peroxisome proliferation may contribute to the hepatocarcinogenic effect of DHEA.
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Mayer D, Degiorgis MP, Meier W, Nicolet J, Giacometti M. Lesions associated with infectious keratoconjunctivitis in alpine ibex. J Wildl Dis 1997; 33:413-9. [PMID: 9249685 DOI: 10.7589/0090-3558-33.3.413] [Citation(s) in RCA: 22] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/05/2023]
Abstract
Following a severe infectious keratoconjunctivitis (IKC) epizootic in free-ranging alpine ibex (Capra ibex ibex) in Switzerland in 1993, 19 animals were examined from six different populations. Mucopurulent exudates, reddened conjunctiva and mononuclear inflammatory cell infiltration in the conjunctiva and the limbic area were observed in mild cases. In more severe cases, lesions ranged from perilimbic neovascularization to corneal edema, erosion, ulceration and neovascularization accompanied by infiltration of neutrophils. Sometimes an iridocyclitis was observed. In the most advanced stages, the cornea was perforated and an anterior synechia was present. Lesions found in ibex affected with IKC indicated a non-generalized, specific ocular disease. The other organs investigated did not show alterations suggestive of changes induced by agents which might cause IKC, including Chlamydia spp. and Mycoplasma. spp. The microbiological findings indicate that Mycoplasma conjunctivae is the primary pathogenic agent causing IKC in this species in Switzerland.
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Abstract
Isolated talus fractures are very uncommon and are usually associated with severe trauma. Five cases of isolated talus fracture associated with relatively minor trauma are reported. These five patients had one clinical sign in common, pain out of proportion to the severity of their injury. The treatment of talus fractures is reviewed.
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Mayer D. Testing the power of belief. Science 1997; 276:881. [PMID: 9163029] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [MESH Headings] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/04/2023]
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Swierczynski J, Kochan Z, Mayer D. Dietary alpha-tocopherol prevents dehydroepiandrosterone-induced lipid peroxidation in rat liver microsomes and mitochondria. Toxicol Lett 1997; 91:129-36. [PMID: 9175849 DOI: 10.1016/s0378-4274(97)03882-4] [Citation(s) in RCA: 15] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/04/2023]
Abstract
Dehydroepiandrosterone (DHEA), an adrenal steroid, causes lipid peroxidation in rat liver microsomes and mitochondria and induces hepatocarcinogenesis. It was investigated whether alpha-tocopherol, a naturally occurring free radical chain terminator, could decrease lipid peroxidation. When DHEA-free diet supplemented with increasing concentrations of alpha-tocopherol (25, 50, 100, 200, 400 and 1000 mg/kg diet) was fed to rats for 7 days, a marked lipid peroxidation (measured as thiobarbituric acid reactive substances formation) was observed at concentrations 25 and 50 mg/kg in liver microsomes and mitochondria isolated from these animals. Lipid peroxidation was significantly reduced at concentrations > or = 100 mg/kg. When DHEA (500 mg/kg diet) was fed to rats simultaneously with increasing concentrations of alpha-tocopherol, strong lipid peroxidation was observed at alpha-tocopherol concentrations < or = 200 mg/kg diet. However, microsomes and mitochondria isolated from livers of rats fed alpha-tocopherol at doses of 400 and 1000 mg/kg diet produced only negligible amounts of thiobarbituric acid reactive substances. The data show that high concentrations of alpha-tocopherol in the diet decrease DHEA-induced microsomal and mitochondrial lipid peroxidation. Our results support the concept that alpha-tocopherol can protect against DHEA-induced lipid peroxidation and consequently against steroid-induced liver cell damage and, perhaps, also tumour development.
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Muñoz NM, Douglas I, Mayer D, Herrnreiter A, Zhu X, Leff AR. Eosinophil chemotaxis inhibited by 5-lipoxygenase blockade and leukotriene receptor antagonism. Am J Respir Crit Care Med 1997; 155:1398-403. [PMID: 9105085 DOI: 10.1164/ajrccm.155.4.9105085] [Citation(s) in RCA: 63] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/04/2023] Open
Abstract
We studied the effects of the 5-lipoxygenase inhibition and sulfidopeptidyl leukotriene receptor antagonism on lumenal chemotaxis of eosinophils in 124 guinea pig tracheal explant preparations from 62 animals. Cell migration was assessed histologically and by differential cell count, and airway narrowing was measured by calibrated micrometry. Intralumenal instillation of the chemotaxin, formyl-met-leu-phe (FMLP) caused migration of 163,509 +/- 18,103 eosinophils/cm segment (eos/cm) versus 15,443 +/- 3,557 eos/cm for segments receiving vehicle only (p < 0.001). Coincubation of FMLP with zileuton, a selective inhibitor of 5-lipoxygenase, caused a concentration-related inhibition of eosinophil migration. At 10(-10) M zileuton, cell migration caused by FMLP was decreased by 57% and nearly complete reduction to 17,200 +/- 3,620 eos/cm resulted after 10(-6) M zileuton (p < 0.001 versus FMLP). Lumenal narrowing caused by FMLP (15.3 +/- 3.4%) was attenuated maximally to 1.15 +/- 2.51% after 10(-8) M zileuton (p < 0.02). In 36 preparations, concentration of leukotriene B4 (LTB4) was measured in treated tracheal perfusate. LTB4 secretion caused by FMLP was 6.4 +/- 0.48 pg/ml versus 3.32 +/- 0.89 pg/ml for buffer control at 5 min (p < 0.02) and was undetectable 120 min after activation with FMLP. Blockade of LTB4-receptor with the selective antagonist, LTB4 dimethyl amide, caused > 90% inhibition of eosinophil migration (p < 0.001). Comparable results were obtained with zafirlukast, an LTD4-receptor antagonist. Our data demonstrate that both LTB4 and LTD4 facilitate eosinophil migration from lamina propria to lumen caused by the chemotaxin, FMLP, and that LTB4-induced eosinophil migration is accompanied by initial lumenal secretion of LTB4.
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Mayer D, Klimek F, Rempel A, Bannasch P. Hexokinase expression in liver preneoplasia and neoplasia. Biochem Soc Trans 1997; 25:122-7. [PMID: 9056856 DOI: 10.1042/bst0250122] [Citation(s) in RCA: 20] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/03/2023]
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