RESUMO
The influence of selective oral antimicrobial prophylaxis (SOAP) and systemic antibiotic treatment (SAT) on the intestinal flora of fourteen granulocytopenic patients was investigated. For SOAP, patients received Cotrimoxazole, Polymyxin and Nystatin; Gentamicin, Ticarcillin and Cefuroxime were administered for SAT. Under SOAP, a complete elimination of Enterobacteriaceae and a marked reduction of yeasts and staphylococci was found. A reduction in the number of anaerobic species was also observed; however, the concentration of anaerobic bacteria remained constant. In contrast, additional systemic antibiotic treatment caused a significant reduction of aerobic as well as anaerobic bacteria, except for microorganisms pathogenic to neutropenic patients (i.e. Staphylococcus epidermidis and Candida sp.). The fecal concentration of beta-aspartylglycine was inversely correlated with the presence of anaerobic bacteria.
Assuntos
Antibacterianos/uso terapêutico , Bactérias/efeitos dos fármacos , Dipeptídeos/metabolismo , Fezes/microbiologia , Leucemia/microbiologia , Doença Aguda , Adolescente , Adulto , Infecções Bacterianas/etiologia , Infecções Bacterianas/prevenção & controle , Quimioterapia Combinada/uso terapêutico , Fezes/metabolismo , Feminino , Humanos , Leucemia/complicações , Leucemia/metabolismo , Masculino , Pessoa de Meia-IdadeRESUMO
5-Aminosalicylic acid presently is believed to represent the therapeutically active moiety of the sulfasalazine molecule in the treatment of inflammatory bowel disease. The metabolism of this compound, however, has not been studied in detail. In this paper we provide evidence that 5-aminosalicylic acid is acetylated to N-acetyl-aminosalicylic acid in homogenates from colonic biopsy specimens (370 +/- 20 nmol/g wet wt or 2.9 +/- 0.9 nmol/mg.min, n = 10), whereas acetylation in fecal samples was only small (13.0 +/- 3.0 nmol/g). Mucosal N-acetylation was rapid, cofactor- and pH-dependent, and could be enriched in the cytosolic fraction. In contrast, fecal acetylation was slow and did not depend on the presence of acetyl-coenzyme A. There were neither significant differences of acetylation between patients and controls nor a significant correlation to the individual acetylation phenotype. From our results we believe that presystemic acetylation of 5-aminosalicylic acid may be mainly mediated by a colonic mucosal enzyme and only to a small extent by fecal (bacterial) processes.
Assuntos
Ácidos Aminossalicílicos/metabolismo , Colo/metabolismo , Doenças Inflamatórias Intestinais/metabolismo , Acetilação , Cromatografia Líquida de Alta Pressão , Fezes/metabolismo , Humanos , Doenças Inflamatórias Intestinais/tratamento farmacológico , Mucosa Intestinal/metabolismo , Mesalamina , Sulfassalazina/uso terapêuticoRESUMO
Intestinal protein loss was measured by means of faecal alpha 1-antitrypsin clearance (alpha 1 ATC) in patients with various gastrointestinal diseases. In healthy controls and in patients with various gastrointestinal diseases there is a remarkable intraindividual fluctuation of the faecal protein loss from day to day. Alpha 1 AT clearance calculated from a three-day stool collection is usually sufficient to indicate enteric protein loss in Crohn's disease, ulcerative colitis, celiac sprue, and Whipple's disease. However, in two patients with intermittent diarrhea coinciding with edema and hypalbuminemia excessive enteric protein loss was observed on one day during a two week stool sampling period only. In one of these patients suction biopsies showed histologically intestinal lymphangiectasia of a 10 cm segment of the upper jejunum. The alpha 1 ATC is a suitable and cheap method to determine enteric protein loss without the use of radioactive tracers and therefore can be used in clinics without departments of nuclear medicine. In contrast to the conventional Gordon test the use of the endogenous marker alpha 1 AT facilitates the determination of faecal protein loss over long time periods, which might be of value in the diagnosis of intermittent occurring enteric protein loss. Furthermore, the endogenous marker alpha 1 AT is of use in following the course of illness and in monitoring the efficacy of therapy in patients with enteric protein loss.
Assuntos
Fezes/metabolismo , Enteropatias Perdedoras de Proteínas/metabolismo , alfa 1-Antitripsina/metabolismo , Adulto , Doença Celíaca/metabolismo , Colite Ulcerativa/metabolismo , Doença de Crohn/metabolismo , Úlcera Duodenal/metabolismo , Feminino , Humanos , Masculino , Úlcera Péptica Hemorrágica/metabolismo , Enteropatias Perdedoras de Proteínas/diagnóstico , Albumina Sérica/metabolismo , Doença de Whipple/metabolismoRESUMO
The kinetics and metabolism of butylated hydroxyanisole (BHA) have been compared between man and rats. Oral doses of 2, 20 or 200 mg BHA/kg body weight were administered to male Wistar rats and a single oral dose of 0.5 mg/kg body weight was administered to human volunteers (non-smoking males). Following oral administration of 2 or 20 mg BHA/kg body weight to rats, no plasma BHA profiles were observed, whereas at the 200 mg BHA/kg body weight dose level plasma BHA peak concentrations between 100 and 400 ng/ml were detected. Plasma BHA peak levels and the area under the curve show that the application of 15% polyethylene glycol-400 as the vehicle produced significantly lower values compared with those obtained using the vehicles, salad dressing, corn oil and dimethylsulphoxide. In man, oral administration of 0.5 mg BHA/kg body weight dissolved in corn oil gave plasma BHA peak concentrations of greater value than 100 ng/ml (range 53 to 255 ng/ml). In rats, 24 hr after dosing 2, 20 or 200 mg BHA/kg body weight the mean BHA concentrations in adipose tissue ranged from 0.7 to 6.8 micrograms/g. In man and rats, BHA was O-demethylated to tert-butylhydroquinone (TBHQ). This is the first study to report that TBHQ is an in vivo metabolite of BHA in rats. Within 4 days following oral administration the total recovery of BHA in the urine and faeces of man (0.5 mg BHA/kg body weight) and rats (200 mg BHA/kg body weight) was 49 +/- 7% and 95 +/- 10% (mean +/- SD) respectively. In rats, BHA was excreted in the urine as free BHA (2%), conjugated BHA (48%) and conjugated TBHQ (9%) and in the faeces as free BHA (36%). In man, BHA was excreted in the urine mainly as conjugated BHA (39%) together with smaller amount of conjugated TBHQ (9%); no free BHA was found in the urine or faeces. In man and rats only the fraction of BHA excreted in urine as conjugates of BHA and TBHQ was qualitatively and quantitatively comparable. Results in this study indicate a considerable difference in the biological fate of BHA following oral administration of high and low doses of BHA in rat and man, respectively.
Assuntos
Hidroxianisol Butilado/farmacocinética , Tecido Adiposo/metabolismo , Adulto , Animais , Hidroxianisol Butilado/sangue , Fezes/metabolismo , Humanos , Hidroquinonas/farmacocinética , Masculino , Ratos , Ratos Endogâmicos , Especificidade da EspécieRESUMO
This paper reports the differences in the fecal excretion of cholesterol and its degradation products in high- and low-responding rhesus monkeys fed diets with and without extra cholesterol. The high-responding monkeys had a great increase in plasma cholesterol concentration when fed a high-cholesterol diet, whereas the low-responders had a small increase when fed the same diet. The results show that low-responding monkeys, when fed high-cholesterol diets, excrete nearly two to three times the amount of cholesterol and its bacterial degradation products in the feces than the high-responding monkeys. We suggest that these two select groups of monkeys may be useful models for the study of the role cholesterol and its bacterial degradation products play in colon cancer.
Assuntos
Bactérias/metabolismo , Colesterol na Dieta/administração & dosagem , Colesterol/metabolismo , Neoplasias do Colo/metabolismo , Fezes/metabolismo , Animais , Colestanos/metabolismo , Colestanol/metabolismo , Macaca mulatta , MasculinoRESUMO
Flavone acetic acid (FAA) is a novel antitumor agent with broad solid-tumor activity. However, this drug has shown a steep dose-response curve in preclinical trials, with a narrow sublethal window of efficacy. To investigate this threshold behavior, we studied various aspects of FAA pharmacology in mice after i.v. administration. Mice bearing advanced-stage s.c. colon 38 adenocarcinoma were treated at four dose levels (39, 65, 108 and 180 mg/kg), and only the highest dose produced significant antitumor activity, showing a steep dose-response curve. Using an HPLC assay, FAA pharmacokinetics in both plasma and tumors were found to be dose-dependent. As the dose increased, there was a decrease in both total body clearance and volume of distribution at steady state. The increase in tumor area under the curve (AUC) was more pronounced than the corresponding increase in plasma AUC, showing a better tumor exposure to FAA at high doses. The distribution of FAA in normal tissues showed a short-term retention in the liver and kidneys; low concentrations were observed in the heart, spleen, and brain, with some retention in the latter. The highest FAA concentrations were found in the gastrointestinal (GI) tract, mainly in the duodenum, suggesting an important biliary excretion of the drug. Various possible causes of FAA nonlinear pharmacokinetics were investigated. Serum protein binding was high (79%) and remained constant up to 100 micrograms/ml, but decreased thereafter at higher FAA concentrations, e.g., 76% at 500 micrograms/ml and 64% at 1,000 micrograms/ml. Urinary and biliary clearances were dose-dependent and decreased 5- and 9-fold, from the 39- to the 180-mg/kg dose levels, respectively. A direct assessment of FAA enterohepatic circulation using intercannulated mice showed that 27% of the plasma AUC was accounted for by enterohepatic circulation. FAA acyl glucuronide was identified as the major metabolite in mice and was found to contribute to the nonlinear pharmacokinetics due to its facile hydrolysis under physiological conditions, regenerating FAA. In conclusion, the steep FAA dose-response curve was found to be caused by dose-dependent pharmacokinetics in mice. The nonlinear pharmacokinetics of this drug was attributed to a dose-dependent decrease in both urinary and biliary clearances, concentration-dependent serum protein binding, enterohepatic circulation, and the instability of FAA acyl glucuronide under physiological conditions forming a futile cycle.(ABSTRACT TRUNCATED AT 400 WORDS)
Assuntos
Antineoplásicos/farmacologia , Flavonoides/farmacologia , Adenocarcinoma/tratamento farmacológico , Adenocarcinoma/metabolismo , Animais , Bile/metabolismo , Proteínas Sanguíneas/metabolismo , Cromatografia Líquida de Alta Pressão , Neoplasias do Colo/tratamento farmacológico , Neoplasias do Colo/metabolismo , Relação Dose-Resposta a Droga , Fezes/metabolismo , Flavonoides/farmacocinética , Flavonoides/uso terapêutico , Mucosa Gástrica/metabolismo , Glucuronatos/urina , Mucosa Intestinal/metabolismo , Taxa de Depuração Metabólica , Camundongos , Camundongos Endogâmicos C57BLRESUMO
Correlation studies suggest that fecal mutagenicity is increased in groups eating high-fat diets, the same groups who are often found to have high colorectal cancer incidence and mortality. The fecapentaenes are the best characterized class of fecal mutagens, but the relationship of dietary fat intake to the excretion of these potent genotoxins is unknown. We studied the effect of changes in amount and type of dietary fat on fecapentaene levels in 31 premenopausal women 20-40 years of age who participated in a controlled feeding study. After a pre-diet free-living period lasting 1 menstrual cycle, women were placed on a high-fat (40% energy from fat) diet for 4 menstrual cycles and then switched to a low-fat (20% energy from fat) diet for an additional 4 menstrual cycles. One-half the subjects were maintained throughout the study at a ratio of polyunsaturated-to-saturated fatty acids (P/S ratio) of 1.0, the other half at 0.3; body weight was constant. All meals during the controlled diet periods were prepared at the Human Study Facility of the Beltsville Human Nutrition Research Center. Fecapentaene and fecapentaene precursor levels were measured in acetone extracts from 3-day pooled stool samples collected during the study. No differences in fecapentaene or precursor levels were observed between the high- and low-fat diets at either P/S ratio. Fecapentaene and precursor levels were higher while on controlled diets than during the pre-diet free-living period, and levels declined again in the post-diet free-living period. We conclude that dietary fat has no significant effect on fecapentaene or precursor levels in acetone extracts of stool in premenopausal women. The effect of other dietary or non-dietary factors on fecapentaenes remains unknown.
Assuntos
Gorduras na Dieta/metabolismo , Mutagênicos/metabolismo , Polienos/metabolismo , Adulto , Ácidos Graxos Insaturados/metabolismo , Fezes/metabolismo , Feminino , Humanos , Fatores de TempoRESUMO
The effect of a diet low in total fat and high in complex carbohydrates on the excretion of bile acids and neutral sterols and on serum lipids was studied in women, 46-47 years old, who were consuming a mixed Western diet. Participants kept an initial 3-day food record while consuming their normal diet (pre-diet period). During the dietary intervention period (experimental diet) which lasted for 26 days, all volunteers consumed a low-calorie, low-fat (less than 10% of total calories), high-fiber (37 g/day, high-carbohydrate diet. At the 1-year follow-up, the participants completed another 3-day food record, which indicates that these volunteers maintained their caloric and fat intake at levels slightly higher than the experimental diet, but lower than the pre-diet period. Individual 24-hr fecal samples for 2 days and blood samples were collected from the volunteers during each dietary period. Fecal samples were analyzed for neutral sterols and bile acids, and blood samples were analyzed to ascertain cholesterol and triglyceride levels. There were no significant differences in the excretion of neutral sterols between the dietary periods. Fecal secondary bile acids were significantly lower during the experimental and follow-up diet periods compared with the pre-test diet period. Serum cholesterol levels were significantly lower during the experimental and follow-up diet periods than during the pre-test diet period. These results suggest that switching from a high-fat, low-fiber diet to a low-fat, high-fiber diet can reduce the excretion of bile acids which are thought to be involved in the promotion of colon cancer.
Assuntos
Ácidos e Sais Biliares/metabolismo , Carboidratos da Dieta/administração & dosagem , Gorduras na Dieta/administração & dosagem , Fibras na Dieta/administração & dosagem , Fezes/metabolismo , Esteróis/metabolismo , Idoso , Colesterol/sangue , Neoplasias do Colo/etiologia , Gorduras na Dieta/efeitos adversos , Feminino , Humanos , Concentração de Íons de Hidrogênio , Pessoa de Meia-Idade , Triglicerídeos/sangueRESUMO
Steatorrhea and azotorrhea are evaluated, by Van de Kamer and Kjendalh methods, in 24 patients affected by cystic fibrosis in the diagnosis and in their evolution. High values were obtained for steatorrhea in 87.5% of the cases and for azotorrhea in the 79.1% at the moment of diagnosis. Steatorrhea and azotorrhea have been correlated obtaining a high statistic significant for p less than 0.01 in the diagnosis and in patients who followed treatment with the same medication, not being significative for all patients during their evolution. With results obtained, determination of fecal nitrogen, is positively evaluated not only in the diagnosis but also in the evolution of these patients to obtain an optimum nutritious condition.
Assuntos
Doença Celíaca/metabolismo , Fibrose Cística/metabolismo , Fezes/metabolismo , Nitrogênio/metabolismo , Doença Celíaca/diagnóstico , Criança , Pré-Escolar , Fibrose Cística/diagnóstico , Fezes/análise , Feminino , Humanos , Lactente , Metabolismo dos Lipídeos , Lipídeos/análise , Masculino , Nitrogênio/análiseRESUMO
In 10 mongrel dogs, massive resection of small intestine was performed by removing 90% of its length. Following a period of approximately 2 months, the animals presented excessive steatorrhea and severe cachexia. Construction of a valve using a local transposition flap within the intestinal lumen near the colon resulted in a detainment of weight loss and steatorrhea. The animals were kept under observation over a period of 4 months.
Assuntos
Intestinos/cirurgia , Síndromes de Malabsorção/cirurgia , Síndrome do Intestino Curto/cirurgia , Retalhos Cirúrgicos , Animais , Peso Corporal , Fezes/metabolismo , Intestinos/patologia , Intestinos/fisiopatologia , Metabolismo dos Lipídeos , Pressão , Síndrome do Intestino Curto/patologia , Síndrome do Intestino Curto/fisiopatologiaRESUMO
A 29-yr-old man with neurological symptoms that included tremor, dysarthria, and loss of consciousness was diagnosed as having variegate porphyria, because of increased urinary excretion of delta-aminolevulinic acid, porphobilinogen, uroporphyrin, and coproporphyrin, and increased fecal uro-, copro-, and protoporphyrins. He showed marked retention of indocyanine green (R15 min: 53%-78%) and bromosulfophthalein (R45 min: 24%-10%) as well. The kinetic analysis revealed that both hepatic uptake and hepatic excretion were decreased for both dyes. Results of other liver function tests were unremarkable except for intermittent hyperbilirubinemia (0.7-3.3 mg/100 ml), of which the ratio of conjugated and unconjugated fraction was between 0.7 and 1.2. Binding of serum protein and indocyanine green or bromosulfophthalein was normal. An angiographic and scintigraphic study of the liver was normal. A minimal deposition of hemosiderin pigment was found in liver biopsy specimen without other abnormalities. Deposition of porphyrin was not present in the liver. Plasma exchange and erythrocytapheresis did not show any beneficial effects on the clinical and laboratory abnormalities of the patient. A possible relationship between variegate porphyria and defective hepatic anion transport is discussed.
Assuntos
Hepatopatias/metabolismo , Porfirias/metabolismo , Adulto , Ânions , Transporte Biológico , Fezes/metabolismo , Humanos , Hepatopatias/terapia , Testes de Função Hepática , Masculino , Troca Plasmática , Porfirias/patologia , Porfirias/terapia , Porfirinas/metabolismoRESUMO
Because of potential significance of fecal mutagens and secondary bile acids in the pathogenesis of colonic cancer and of inverse association between dietary fiber and colonic cancer risk, the effect of dietary wheat and rye fiber on fecal mutagenic activity and bile acid levels was studied in 15 healthy men and women who were consuming high fat/moderately low fiber diets and excreting high levels of fecal mutagens and bile acids. Each participant provided two 24-h stool specimens and a 3-day diet record while consuming their normal diet (control). All subjects were then asked to consume their normal diet plus 11 g of supplemental fiber per day in the form of whole grain bread for 4 weeks. During the last week of diet intervention, each subject provided two 24-h stool specimens and a 3-day dietary record. Fecal samples collected from both periods were analyzed for bile acids and for mutagens using Salmonella typhimurium strains TA98 and TA100 with and without microsomal activation. The concentration of fecal secondary bile acids was significantly lower during the fiber supplemental period in all subjects. Fiber supplementation also inhibited the fecal mutagenic activity in TA100 and TA98 with and without microsomal activation. Thus, the increased fiber intake in the form of whole wheat and rye bread may reduce the production and/or excretion of fecal mutagens and decrease the concentration of fecal secondary bile acids in humans.
Assuntos
Ácidos e Sais Biliares/metabolismo , Neoplasias do Colo/etiologia , Fibras na Dieta/metabolismo , Fezes/metabolismo , Mutagênicos/metabolismo , Gorduras na Dieta/metabolismo , Proteínas Alimentares/metabolismo , Ingestão de Energia , Feminino , Humanos , Masculino , Testes de MutagenicidadeRESUMO
[3H]Benzo(a)pyrene [B(a)P] disposition and metabolism were investigated in male Sprague-Dawley rats. [3H]B(a)P, in a vehicle of triethylene glycol, was administered by intratracheal instillation (1 microgram/kg body weight), and the amount of radioactivity in various organs was determined at timed intervals between 5 and 360 min. Elimination of radioactivity from lungs was biphasic with half-lives of 5 and 116 min. Radioactivity in liver increased rapidly, reaching a maximum of 21% of the dose within 10 min after instillation and decreasing thereafter until less than 5% of the dose was detected at 360 min after instillation. The carcass accounted for 15-30% of the dose within the time intervals investigated. Toxicokinetic parameters to describe elimination of unmetabolized B(a)P from blood following intratracheal administration were found to be very similar to those calculated following i.v. administration. B(a)P metabolites in lung, liver, and intestinal contents were identified. Notably, quinones were at highest concentrations in both lung and liver 5 min after instillation, accounting for 12 and 7% of organic extractable material, respectively. B(a)P disposition was also investigated in animals with and without biliary cannulas. Distribution patterns among organs were similar though the amount excreted in bile and intestinal contents was 74 and 40% of the dose, respectively. Types of metabolites in bile and intestinal contents were identified and compared. Lower fractions of the administered dose were detected as thioether and glucuronic acid conjugates in intestinal contents than in bile, indicating that enterohepatic circulation of B(a)P metabolites was occurring.
Assuntos
Benzo(a)pireno/metabolismo , Animais , Benzo(a)pireno/administração & dosagem , Bile/metabolismo , Fezes/metabolismo , Mucosa Intestinal/metabolismo , Fígado/metabolismo , Pulmão/metabolismo , Masculino , Taxa de Depuração Metabólica , Ratos , Distribuição Tecidual , TraqueiaRESUMO
Two completely random digestion trials were conducted, each with 12 beef steers (325 kg initial weight), to measure changes in digestibilities of fat and of forage components when fat was added to diets containing 62 to 76% wheat straw. Trial 1 diets contained either no added fat or 6.3% added fat from whole cottonseed (30% of the diet), cottonseed oil or animal fat; diets were formulated to contain equal levels of cottonseed hulls and cottonseed meal. Trial 2 diets contained 0, 2, 4 or 8% added animal fat. In all forms and at all levels, added fat increased apparent digestibility of dietary lipid (P less than .05). However, estimated true digestibility of lipid decreased (from 94 to 71%) as added fat was increased from 0 to 8% (P less than .05). Up to 6.3% added fat increased digestible energy (DE) content of the diet. Fat additions of 2 and 4% increased daily DE intake (P less than .05) and did not depress digestibility of diet components (P greater than .05). Fat additions of 6.3% or greater, either as free fats or as whole cottonseed, reduced (P less than .05) mean acid detergent fiber digestibility from 40 to 28%. In addition to depressing fiber digestibility, 8% added fat reduced (P less than .05) digestibilities of dry matter (from 54 to 47%), organic matter (60 to 52%) and gross energy (60 to 51%). Oil fed as whole cottonseed caused digestibility depressions similar to free fat addition at the same level.(ABSTRACT TRUNCATED AT 250 WORDS)
Assuntos
Bovinos/metabolismo , Gorduras na Dieta/metabolismo , Fibras na Dieta/metabolismo , Ração Animal , Animais , Óleo de Sementes de Algodão/metabolismo , Digestão , Ingestão de Energia , Fezes/metabolismo , Absorção Intestinal , TriticumRESUMO
A study was made of the role of biocomponents of bile, urine and feces in the elimination of plutonium and americium from the organism. Plutonium 239 and americium 241 were separated in bile due to higher tropism of plutonium to low molecular weight ligands, and of americium, to a protein-containing fraction. The status of plutonium excreted in feces was the same as the physicochemical status of americium. Plutonium 239 and americium 241 eliminated in urine were in a completely ultrafiltered state.
Assuntos
Amerício/metabolismo , Bile/metabolismo , Fezes/metabolismo , Plutônio/metabolismo , Amerício/urina , Animais , Plutônio/urina , RatosRESUMO
The objective of this study was to evaluate age-related changes in the in vivo metabolism and excretion of allyl isothiocyanate (AITC), which is used as a model compound to assess glutathione conjugation. AITC is a constituent of oil of mustard and a food additive that has been shown to induce transitional cell papillomas in the urinary bladder of male Fischer rats. Male Fischer rats, ages 3, 16, and 27 months, were dosed orally with 14C-AITC (25 mg/kg). Urine, feces, volatiles, and expired air were collected for 72 hr. Biliary excretion was also examined after iv administration of 10 mg/kg of 14C-AITC. There was no significant difference between these age groups in the percentage of the total dose of AITC eliminated in urine, which is the major route of excretion. The percentage of the dose excreted as volatiles increased in the 27-month animals. These animals also showed a decrease in the production of 14CO2. An age-related decrease in fecal excretion of AITC-derived radioactivity was observed. However, the percentage of the dose excreted in bile increased at 16 months and then decreased in the senescent rats as compared to the 3-month age group. The age-related decrease in 14CO2 production suggests a change in the oxidative metabolism of AITC in senescent animals. However, there was no change in the relative amounts of mercapturic acid excreted in urine, suggesting that glutathione conjugation was unchanged with age.(ABSTRACT TRUNCATED AT 250 WORDS)
Assuntos
Glutationa/metabolismo , Isotiocianatos , Tiocianatos/metabolismo , Fatores Etários , Animais , Bile/metabolismo , Fezes/metabolismo , Fígado/metabolismo , Masculino , Taxa de Depuração Metabólica , Ratos , Tiocianatos/urinaRESUMO
A 32 year old woman with severe aplastic anaemia required frequent transfusions and consequently developed hyperferrioxaemia (54 microMol/l) and hyperferritinaemia (1,700 ng/ml). For the treatment of transfusion siderosis she was given 18 high dose courses each comprising 35 g of desferrioxamine. Because of pre-existing thrombocytopenia (platelet count 5 X 10(9)/l) the iron chelating agent was given by continuous intravenous infusion over 3 1/2 days. High dose desferrioxamine had to be abandoned because of severe bone pain. The desferrioxamine infusions achieved a negative iron balance, iron loss after each infusion being 100 to 200 mg in the urine and 400 mg in the faeces. Serum iron and ferritin concentrations fell almost to normal. This report shows that faecal iron excretion must be taken into account in assessing the balance of iron input and output during desferrioxamine treatment.
Assuntos
Anemia Aplástica/terapia , Desferroxamina/administração & dosagem , Siderose/tratamento farmacológico , Adulto , Anemia Aplástica/patologia , Medula Óssea/patologia , Desferroxamina/efeitos adversos , Fezes/metabolismo , Feminino , Ferritinas/sangue , Humanos , Ferro/metabolismo , Siderose/metabolismoRESUMO
Weanling male F344 rats were fed the sodium, potassium, or calcium salt of saccharin or acid saccharin as 5% of the diet by weight for 10 weeks. Sodium saccharin induced significant urinary bladder epithelial proliferation as determined by the labelling index following [3H]thymidine incorporation and by light and scanning electron microscopic evaluation. Potassium saccharin also significantly increased the labelling index but less than the sodium salt. Calcium saccharin and acid saccharin did not significantly increase the labelling index. Similar differences were evident by light and scanning electron microscopy. These differences were not due to differences in the level of saccharin excretion in the urine following feeding of the various salts. Differences in urinary pH and urinary concentration of sodium and calcium were observed between rats fed the various forms of saccharin.
Assuntos
Sacarina/administração & dosagem , Bexiga Urinária/efeitos dos fármacos , Animais , Cálcio , Ciclo Celular/efeitos dos fármacos , Diarreia/induzido quimicamente , Epitélio/patologia , Fezes/metabolismo , Hiperplasia , Potássio , Ratos , Sacarina/metabolismo , Sacarina/urina , Sais , Sódio , Relação Estrutura-Atividade , Bexiga Urinária/patologiaRESUMO
Literature regarding the biochemistry of aluminum and eight similar ions is reviewed. Close and hitherto unknown similarities were found. A hypothetical model is presented for the metabolism, based on documented direct observations of Al3+ and analogies from other ions. Main characteristics are low intestinal absorption, rapid urinary excretion, and slow tissue uptake, mostly in skeleton and reticuloendothelial cells. Intracellular Al3+ is probably first confined in the lysosomes but then slowly accumulates in the cell nucleus and chromatin. Large, long-lived cells, e.g., neurons, may be the most liable to this accumulation. In heterochromatin, Al3+ levels can be found comparable to those used in leather tannage. It is proposed that an accumulation may take place at a subcellular level without any significant increase in the corresponding tissue concentration. The possible effects of this accumulation are discussed. As Al3+ is neurotoxic, the brain metabolism is most interesting. The normal and the lethally toxic brain levels of Al3+ are well documented and differ only by a factor of 3-10. The normal brain uptake of Al3+ is estimated from data on intestinal uptake of Al3+ and brain uptake of radionuclides of similar ions administered intravenously. The uptake is very slow, 1 mg in 36 years, and is consistent with an assumption that Al3+ taken up by the brain cannot be eliminated and is therefore accumulated. The possibility that Al3+ may cause or contribute to some specific diseases, most of them related to aging, is discussed with the proposed metabolic picture in mind.