Relationship between the Balance of Hypertrophic/Hyperplastic Adipose Tissue Expansion and the Metabolic Profile in a High Glucocorticoids Model.

Adipose tissue (AT) expansion is the result of two processes: hyperplasia and hypertrophy; and both, directly or indirectly, depend on the adipogenic potential of adipocyte precursor cells (APCs). Glucocorticoids (GCs) have a potent stimulatory effect on terminal adipogenesis; while their effects on early stages of adipogenesis are largely unknown. In the present work, we study, in a model of high GC levels, the adipogenic potential of APCs from retroperitoneal AT (RPAT) and its relationship with RPAT mass expansion. We employed a model of hyper-adiposity (30- and 60-day-old rats) due to high endogenous GC levels induced by neonatal treatment with l-monosodium glutamate (MSG). We found that the RPAT APCs from 30-day-old MSG rats showed an increased adipogenic capacity, depending on the APCs' competency, but not in their number. Analyses of RPAT adipocyte diameter revealed an increase in cell size, regardless of the rat age, indicating the prevalence of a hypertrophic process. Moreover, functional RPAT alterations worsened in 60-day-old rats, suggesting that the hyperplastic AT expansion found in 30-day-old animals might have a protective role. We conclude that GCs chronic excess affects APCs' adipogenic capacity, modifying their competency. This change would modulate the hyperplastic/hypertrophic balance determining healthy or unhealthy RPAT expansion and, therefore, its functionality.

Brain and muscle redox imbalance elicited by acute ethylmalonic acid administration.

Ethylmalonic acid (EMA) accumulates in tissues and biological fluids of patients affected by short-chain acyl-CoA dehydrogenase deficiency (SCADD) and ethylmalonic encephalopathy, illnesses characterized by neurological and muscular symptoms. Considering that the mechanisms responsible for the brain and skeletal muscle damage in these diseases are poorly known, in the present work we investigated the effects of acute EMA administration on redox status parameters in cerebral cortex and skeletal muscle from 30-day-old rats. Animals received three subcutaneous injections of EMA (6 µmol/g; 90 min interval between injections) and were killed 1 h after the last administration. Control animals received saline in the same volumes. EMA administration significantly increased thiobarbituric acid-reactive substances levels in cerebral cortex and skeletal muscle, indicating increased lipid peroxidation. In addition, carbonyl content was increased in EMA-treated animal skeletal muscle when compared to the saline group. EMA administration also significantly increased 2',7'-dihydrodichlorofluorescein oxidation and superoxide production (reactive species markers), and decreased glutathione peroxidase activity in cerebral cortex, while glutathione levels were decreased only in skeletal muscle. On the other hand, respiratory chain complex I-III activity was altered by acute EMA administration neither in cerebral cortex nor in skeletal muscle. The present results show that acute EMA administration elicits oxidative stress in rat brain and skeletal muscle, suggesting that oxidative damage may be involved in the pathophysiology of the brain and muscle symptoms found in patients affected by SCADD and ethylmalonic encephalopathy.

A Comparison of the Bleaching Effectiveness of Chlorine Dioxide and Hydrogen Peroxide on Dental Composite

This study was carried out to verify if composites could be bleached using chlorine dioxide as compared with hydrogen peroxide. 3M ESPE Filtek Z350 Universal Restorative discs were prepared (n=40), with dimensions 5 mm diameter x 2 mm thickness. The discs were divided into 4 groups of 10 discs each. Color assessment was performed by CIEDE2000. The discs were stained with coffee, tea, wine and distilled water (control) solutions for 14 days, 5 hours daily. Color assessment was repeated on stained discs and followed by bleaching of 5 discs from each group using chlorine dioxide and hydrogen peroxide in-office systems. Finally, a last color assessment was performed and compared statistically. DE2000 after bleaching was very close to baseline for both the bleaching agents, although chlorine dioxide showed better results than hydrogen peroxide. After staining, there was a clinically significant discoloration (∆E2000≥3.43) for the tea, coffee and wine groups, and discoloration (∆E2000) was seen more in the wine group as compared to tea and coffee. Overall, the control group (distilled water) had the least color change in the three intervals. After bleaching, the color in all specimens returned close to the baseline. The color differences between bleaching and baseline were less than 3.43 for all groups. The obtained results show that chlorine dioxide is slightly superior to hydrogen peroxide in the bleaching of composites, while maintaining the shade of the composite close to the baseline.

Este estudo foi realizado para verificar se resinas compostas podem ser clareadas com uso do dióxido de cloro, em comparação com peróxido de hidrogênio. Foram preparados discos com resina restauradora Filtek Z350 3M ESPE (n=40), com dimensões 5 mm de diâmetro × 2 mm de espessura. Os discos foram divididos em 4 grupos de 10 discos cada. A avaliação da cor foi realizada por meio do CIEDE2000. Os discos foram manchados com soluções de café, chá, vinho e água destilada (controle) por 5 h diárias durante 14 dias. A avaliação da cor foi repetida nos discos manchados e seguida por clareamento de 5 discos de cada grupo, utilizando dióxido de cloro ou peróxido de hidrogênio pela técnica de consultório. Finalmente, uma última avaliação da cor foi realizada e as técnicas comparadas estatisticamente. DE2000 após o clareamento foi muito próxima ao baseline, para ambos os agentes clareadores, embora o dióxido de cloro tenha mostrado melhores resultados do que o peróxido de hidrogênio. Após o manchamento, houve uma descoloração clinicamente significativa (ΔE2000≥3,43) para os grupos de chá, café e vinho, sendo que o clareamento (ΔE2000) foi melhor obtido com o grupo do vinho, em comparação com chá e café. No geral, o grupo controle (água destilada) teve a menor mudança de cor nos três intervalos. Após o clareamento, a cor em todos os espécimes voltou próxima ao baseline. As diferenças de cor entre o clareamento e o baseline foram inferiores a 3,43 para todos os grupos. Os resultados indicam que o dióxido de cloro é ligeiramente superior ao peróxido de hidrogênio no clareamento de resinas compostas, mantendo a cor próxima à escala do baseline.

Synthesis, characterization, and in vivo evaluation of poly(ethylene oxide-co-glycidol)-platinate conjugate.

Poly(ethylene oxide-co-glycidol) (poly(EO-co-Gly)), a member of polyether polyol (PEP), resembles polyethylene glycol (PEG) in the polymer backbone but distinguishes itself by having multiple pendent groups along the main chain. We showed that this new bioconjugation material is biocompatible by its lack of toxicity on fibroblast cell growth, inactivity in hemolysis, and the absence of side effects after injection in mice. The usefulness of poly(EO-co-Gly) as a polymeric drug carrier was demonstrated via the preparation and characterization of a new anticancer polymer-drug conjugate, poly(EO-co-Gly)-platinate. The drug loading was 9.1-12.6% (cisplatin/conjugate w/w), at least four times higher than a PEG conjugate of similar molecular weight. The aqueous solubility of cisplatin was increased by around 10 folds after conjugation. Platinum complexes were released from the conjugate in a sustained manner over 2 days. The release of active drugs was confirmed by the antitumor activity of poly(EO-co-Gly)-platinate in vitro against HONE-1 (human nasopharyngeal carcinoma) and MCF-7 (human breast cancer), albeit at a potency lower than free cisplatin. Poly(EO-co-Gly)-platinate improved the therapeutic index of cisplatin in vivo. The conjugate had a similar antitumor activity as free cisplatin in nude mice bearing HONE-1 xenografts, and achieved 52% inhibition of tumor growth at the conclusion of the study. While free cisplatin injection caused a severe loss in body weight (>20%), poly(EO-co-Gly)-platinate resulted in mild side effects. These findings support that poly(EO-co-Gly) is a suitable drug carrier.

Nephrotoxicity of heptaplatin: a randomized comparison with cisplatin in advanced gastric cancer.

PURPOSE: Heptaplatin is a newly developed platinum derivative which has been reported to be less toxic than cisplatin. This study was designed to evaluate the nephrotoxicity of heptaplatin in comparison with that of cisplatin. METHODS: Previously untreated advanced gastric cancer patients with normal renal function were randomly assigned into either group I (heptaplatin 400 mg/m(2) i.v. over 1 h on day 1 plus 5-fluorouracil (5-FU) 1000 mg/m(2) per day continuous i.v. from day 1 to day 5), or group II (cisplatin 60 mg/m(2) i.v. over 1 h on day 1 plus 5-FU 1000 mg/m(2) per day continuous i.v. from day 1 to day 5), with the cycles repeated every 4 weeks. Renal function parameters before, during, and after the chemotherapy were compared between the two groups. RESULTS: A total of 99 patients were enrolled in the study, 51 in group I and 48 in group II. The 24-h proteinuria on day 5 was markedly increased in group I (95+/-108 mg/day to 9098+/-4514 mg/day, means+/-SD) in comparison with the increase observed in group II (104+/-148 mg/day to 151+/-102 mg/day), and creatinine clearance showed a greater decrease in group I (83.1+/-23.6 ml/min to 44.9+/-17.3 ml/min) than in group II (89.6+/-22.1 ml/min to 72.8+/-21.0 ml/min). The differences in these parameters between the two groups were statistically significant throughout the subsequent cycles. CONCLUSIONS: Our findings show that nephrotoxicity was more severe in patients treated with heptaplatin 400 mg/m(2) than with cisplatin 60 mg/m(2) when it was combined with 5-FU. Measures to more effectively prevent nephrotoxicity should be developed for the safe use of heptaplatin.

A Phase I study of cis-malonato[(4R,5R)-4,5-bis(aminomethyl)-1,3-dioxolane] platinum(II) in patients with advanced malignancies.

BACKGROUND: A Phase I study of cis-malonato[(4R,5R)-4,5-bis(aminomethyl)-1,3-dioxolane] platinum(II) (SKI 2053R), a new platinum derivative, was performed to determine the maximum tolerated dose (MTD), the dose limiting toxicities (DLTs), and the pharmacokinetic profile of SKI 2053R in patients with advanced, refractory malignancies. METHODS: Twenty-one patients were entered into the study. SKI 2053R was administered with an intravenous infusion over 1 hour every 4 weeks. The SKI 2053R dose was escalated from 40 mg/m(2) up to 480 mg/m(2) using a modified Fibonacci scheme. Pharmacokinetic analysis was done in all patients to determine the total and ultrafiltrable platinum concentrations in both the plasma and the urine. RESULTS: All patients were evaluable for toxicity and response. There was no significant toxicity with dosages up to 360 mg/m(2). At 480 mg/m(2), two of three patients developed Grade 4 hepatotoxicity, Grade 3 leukopenia and thrombocytopenia, and Grade 2 azotemia and proteinuria. Other toxicity included nausea and emesis, but it was controlled with antiemetics. SKI 2053R did not cause significant neurotoxicity or mucositis. There were 4 patients with stable disease among the 21 patients. Plasma decay of the total and free platinum concentrations was best fitted by using a two-compartment, open model. The terminal plasma half-life of the total platinum after SKI 2053R administration ranged from 63.4 hours to 114.1 hours in dosages ranging from 40 mg/m(2) to 480 mg/m(2) without significant dose dependency. However, the terminal plasma half-life of the free platinum concentration showed a significant dose dependent, incremental pattern. The renal excretion of SKI 2053R measured as platinum ranged from 49% to 75% of the administered dose. CONCLUSIONS: The MTD of SKI 2053R was 480 mg/m(2). The major DLTs were hepatotoxicity, nephrotoxicity, and myelosuppression. The recommended starting dose for a subsequent Phase II study is 360 mg/m(2) once every 4 weeks.

Chronic administration of malonic acid produces selective neural degeneration and transient changes in calbindin immunoreactivity in rat striatum.

Adult rats received chronic dialytic delivery devices that exposed the striatum to a 100 mM, 400 mM, or 4 M solution of the reversible succinate dehydrogenase inhibitor malonic acid (MA). Three weeks of exposure to 100 or 400 mM MA produced no significant reduction in striatal cytochrome oxidase staining, whereas striata chronically exposed to 1 and 4 M MA showed a significant and dose-related reduction in cytochrome oxidase staining. In striata exposed to 1 M MA, analysis of regions radial to the necrotic core revealed significant reduction of nissl cell staining with relative sparing of NADPH-diaphorase-containing neurons. Although 100 and 400 mM MA failed to produce lesions, both of these concentrations significantly decreased the number of striatal calbindin (CALB) immunoreactive perikarya. The reduction in CALB immunoreactivity was partly reversed in animals allowed to survive 4 weeks after cessation of exposure to 400 mM MA. These results indicate that, like striatal lesions produced by quinolinic acid, lesions produced by chronic exposure to MA possess a Huntington's disease-like pattern of selective neurodegeneration. In addition, exposure to subthreshold MA concentrations (100 and 400 mM) produce widespread transient changes in striatal CALB that may be associated with a premorbid state of neuronal dysfunction.

Characterization of the excitotoxic potential of the reversible succinate dehydrogenase inhibitor malonate.

Although the mechanism of neuronal death in neurodegenerative diseases remains unknown, it has been hypothesized that relatively minor metabolic defects may predispose neurons to N-methyl-D-aspartate (NMDA) receptor-mediated excitotoxic damage in these disorders. To further investigate this possibility, we have characterized the excitotoxic potential of the reversible succinate dehydrogenase (SDH) inhibitor malonate. After its intrastriatal stereotaxic injection into male Sprague-Dawley rats, malonate produced a dose-dependent lesion when assessed 3 days after surgery using cytochrome oxidase histochemistry. This lesion was attenuated by coadministration of excess succinate, indicating that it was caused by specific inhibition of SDH. The lesion was also prevented by administration of the noncompetitive NMDA antagonist MK-801. MK-801 did not induce hypothermia, and hypothermia itself was not neuroprotective, suggesting that the neuroprotective effect of MK-801 was due to blockade of the NMDA receptor ion channel and not to any nonspecific effect. The competitive NMDA antagonist LY274614 and the glycine site antagonist 7-chlorokynurenate also profoundly attenuated malonate neurotoxicity, further indicating an NMDA receptor-mediated event. Finally, the alpha-amino-3-hydroxy-5-methyl-4-isoxazolepropionate (AMPA) antagonist NBQX (2,3-dihydroxy-6-nitro-7-sulfamoylbenzo(f)-quinoxaline) was ineffective at preventing malonate toxicity at a dose that effectively reduced S-AMPA toxicity, indicating that non-NMDA receptors are involved minimally, if at all, in the production of the malonate lesion. We conclude that inhibition of SDH by malonate results in NMDA receptor-mediated excitotoxic neuronal death. If this mechanism of "secondary" or "weak" excitotoxicity plays a role in neurodegenerative disease, NMDA antagonists and other "antiexcitotoxic" strategies may have therapeutic potential for these diseases.

The results of a randomized double blind controlled trial evaluating malotilate in primary biliary cirrhosis. A European multicentre study group.

One hundred and one patients were included in a double-blind controlled trial to determine whether malotilate (diisopropyl 1,3-dithiol-2-ylidene malonate) is therapeutically effective in primary biliary cirrhosis. Fifty-two patients received malotilate (500 mg three times a day) and 49 patients placebo. The mean follow-up time was 28 months (range 6-46 months). The large majority of patients did not have advanced liver disease since only ten patients were in Child-Pugh class B and none in class C, and the median bilirubin and albumin at entry were normal. Malotilate had no clear effect on pruritus. In malotilate recipients the following statistically significant biochemical changes occurred: alkaline phosphatase decreased 21%, AST 20%, ALT 40%, IgA 12% and IgM 26%. In the placebo group no significant changes occurred. Evaluation of entry and 2-year liver biopsies indicated that malotilate diminished plasma cell and lymphocytic infiltrate and piece-meal necrosis, but had no effect on liver fibrosis. There was no difference in survival or in disease progression according to Child-Pugh criteria. In six patients receiving malotilate, but in none on placebo, treatment was discontinued due to suspected side effects. All patients recovered completely. We conclude that malotilate has an immune-modulating, anti-inflammatory but not anti-fibrotic effect in primary biliary cirrhosis. The clinical relevance of the observed benefits, however, appears too slight to recommend malotilate as single drug therapy in primary biliary cirrhosis.

Treatment of liver disease with malotilate. A pharmacokinetic and pharmacodynamic phase II study in cirrhosis.

Malotilate, a sulphur-containing compound with antifibrotic and hepatoprotective properties in several animal models, has been investigated in cirrhotic patients. Nine patients with cirrhosis of various aetiologies and severity, and 4 healthy volunteers, participated in a pharmacokinetic study. After a single dose of 500 mg malotilate p.o. peak malotilate plasma concentration measured by GC-MS was 35 times higher in patients (median 0.70 micrograms/ml) than in controls (median 0.019 micrograms/ml). The median apparent oral clearance was approximately 50 times lower in cirrhotics (median 2.21/min) than in healthy volunteers (1181/min). The apparent oral clearance was significantly correlated with indicators of portal-systemic shunting, such as the 2-h postprandial serum bile acids and the bioavailability of oral nitroglycerine. Urinary output of the glucuronidated metabolite-(M3), measured by HPLC, was normal in patients, whereas recovery of metabolite-M6 (resulting from ring opening and loss of sulphur) was reduced. Six patients in an open 6-month trial received malotilate 200 mg t.i.d. for 2 months and 400 mg t.i.d. for 4 months. The thrombocyte count increased and serum ferritin level fell in all patients, and serum cholinesterase rose and IgA decreased in 5 of 6. The other indicators of liver function did not show a significant change. Dry skin was the only possible adverse effect. It is concluded that first-pass elimination of malotilate is dramatically reduced in cirrhotics, and that a smaller amount of the drug reaches the liver in such patients. Malotilate was well tolerated, even in patients with advanced disease.

Oral toxicity of malonaldehyde: a 90-day study on mice.

The oral toxicity of malonaldehyde (MA), a product of lipid peroxidation found in some foods, was investigated in a 90-d study on mice, MA as the sodium enol salt was administered in the drinking water to 8-wk-old female Swiss mice at levels calculated to provide 2, 10, 50, 250, or 500 micrograms/g body weight . d. There was no mortality and all groups gained weight at comparable rates except that those that received 500 micrograms/g body weight . d gained more slowly and lost weight after 50 d. Histopathological examination of 27 tissues indicated that the liver was the only organ that underwent dose-dependent changes. All levels of MA induced irregularities (anisokaryosis, hyperchromicity, vesiculation) of hepatic nuclei. Pancreatic lesions consisting primarily of atrophy of the exocrine cells with loss of zymogen granulation occurred in animals which received 500 micrograms MA/g body weight . d. Mild dysplasia of the urinary bladder epithelium was found in all treatment groups. Approximately 1% of the dose was excreted unchanged in the urine at each level of administration.

[Animal experiment studies on the effect of intra-articular injections of antiphlogistic-antirheumatic agents on articular cartilage in vivo]. / Tierexperimentelle Untersuchungen über den Einfluss intraartikulär applizierter Antiphlogistika/Antirheumatika auf den Gelenkknorpel in vivo.

Animal experiments have shown that weekly intraarticular injections of various antiphlogistic/antirheumatic drugs into the knee joint induce progressive degenerative alterations in joint cartilage. The observed degenerations and destructions are most similar to the pathophysiology of osteoarthrosis in humans. By X-ray and macroscopic techniques the degenerative processes can be studied qualitatively and quantitatively. A decrease of joint space is a sensitive and early indicator of osteoarthrosis and showed that 10 weeks after intraarticular application of Ibuprofen, Phenylbutazone, Oxyphenbutazone, Flufenamic acid, Niflumic acid, Na-salicylate, Clofezone, Bumadizone and Dexamethasone the degenerative alterations in the injected knee joints were more severe than by applications of Chloroquine,D-penicillamine, Salicylamide and Indometacin. The degenerative effect on articular cartilage by the investigated drugs can be explained by their inhibitory potency on anabolic metabolism of connective tissue. The results of our animal experiments lead to the conclusion, that antiinflammatory drugs may also in man induce or accelerate degenerative joint diseases especially after long term treatment with high doses of these drugs.