Metallothionein-null mice absorb less Zn from an egg-white diet, but a similar amount from solutions, although with altered intertissue Zn distribution.
(1/88)
The influence of metallothionein (MT) on Zn transfer into non-gut tissues was investigated in MT-null (MT-/-) and normal (MT+/+) mice 4 h after oral gavage of aqueous 65ZnSO4solution at doses of 154, 385, 770 and 1540 nmol Zn per mouse. Zn transfer was not significantly different between MT+/+ and MT-/- mice and was directly proportional to the oral dose (slope = 0.127, r = 0.991; 0. 146, r = 0.994, respectively). Blood 65Zn and plasma Zn concentrations increased progressively in MT-/- mice at doses >154 nmol Zn, reaching levels of 2.4% of oral dose and 60 micromol/L, respectively, at the 1540 nmol Zn dose. The corresponding values for MT+/+ mice were approximately half, 1.0% and 29 micromol/L. Intergenotypic differences were found in tissue distribution of 65Zn within the body; MT-/- mice had higher 65Zn levels in muscle, skin, heart and brain, whereas MT+/+ mice retained progressively more Zn in the liver, in conjunction with a linear increase in hepatic MT up to the highest Zn dose. MT induction in the small intestine reached its maximum at an oral dose of 385 nmol Zn and did not differ at higher doses. Absorption of a 770 nmol 65Zn dose from a solid egg-white diet was only one fourth (MT+/+) and one eighth (MT-/-) of the Zn absorption from the same dose of 65Zn in aqueous solution. MT+/+ mice had greater (P < 0.05) Zn absorption from the egg-white diet than did MT-/- mice, indicating that gut MT confers an absorptive advantage, but only when Zn is incorporated into solid food. (+info)
Gastric decontamination--a view for the millennium.
(2/88)
The management of acute poisoning remains an important part of accident and emergency (A&E) care. Three gastric decontamination procedures have been widely used: gastric lavage, ipecac, and activated charcoal. Their role has recently been reviewed and position statements developed by working groups of the American Academy of Clinical Toxicology and the European Association of Poisons Centres and Clinical Toxicologists. These have important implications for A&E, as they indicate that activated charcoal is now the agent of choice for most poisons, but than in most situations it is probably only effective if given within an hour of overdose. Ipecac is effectively obsolete and gastric lavage has a narrow range of indications, principally for potentially serious amounts of agents not adsorbed by charcoal. Protocols for care of overdose patients should be modified accordingly. (+info)
Effect of activated charcoal alone or given after gastric lavage in reducing the absorption of diazepam, ibuprofen and citalopram.
(3/88)
AIMS: The efficacy of activated charcoal alone, and gastric lavage followed by charcoal in reducing the absorption of diazepam, ibuprofen and citalopram was studied in healthy volunteers. METHODS: In a randomized cross-over study with three phases, nine healthy volunteers were administered single oral doses of 5 mg diazepam, 400 mg ibuprofen and 20 mg citalopram, taken simultaneously after an overnight fast. Thirty minutes later, the subjects were assigned to one of the following treatments: 200 ml water (control), 25 g activated charcoal as a suspension in 200 ml water or gastric lavage followed by 25 g charcoal in suspension given through the lavage tube. Plasma concentrations of diazepam, ibuprofen and citalopram were determined up to 10 h. RESULTS: The AUC(0,10 h) of diazepam was reduced by 27% (P<0.05) by both charcoal alone and charcoal combined with lavage. The increase in plasma diazepam concentration from 0.5 h onwards was prevented by both interventions (P+info)
Gastric decontamination performed 5 min after the ingestion of temazepam, verapamil and moclobemide: charcoal is superior to lavage.
(4/88)
AIMS: The aim was to study the efficacy of gastric lavage and activated charcoal in preventing the absorption of temazepam, verapamil and moclobemide when gastric decontamination was performed immediately after ingestion of the drugs. METHODS: Nine healthy volunteers took part in a randomized cross-over study with three phases. The subjects were administered single oral doses of 10 mg temazepam, 80 mg verapamil and 150 mg moclobemide. Five minutes later, they were assigned to one of the following treatments: 200 ml water (control), 25 g activated charcoal as a suspension in 200 ml water or gastric lavage. Plasma concentrations and the cumulative excretion into urine of the three drugs were determined up to 24 h. RESULTS: The mean AUC(0,24 h) of temazepam, verapamil and moclobemide was reduced by 95.2% (P < 0.01), 92.8% (P < 0.01) and 99. 7% (P < 0.01), respectively, by activated charcoal compared with control. Gastric lavage did not reduce significantly the AUC(0,24 h) of these drugs. The 24 h cumulative excretion of temazepam, verapamil and moclobemide into urine was reduced significantly (P < 0.05) by charcoal but not by gastric lavage. Charcoal reduced the AUC(0,24 h), Cmax and urinary excretion of all three drugs significantly more than lavage. CONCLUSIONS: Activated charcoal is very effective and gastric lavage can be rather ineffective in preventing the absorption of temazepam, verapamil and moclobemide when the treatment is given very rapidly after ingestion of the drugs, before tablet disintegration has occurred. (+info)
Sputum induction for the diagnosis of pulmonary tuberculosis in infants and young children in an urban setting in South Africa.
(5/88)
BACKGROUND: Bacteriological confirmation of pulmonary tuberculosis is difficult in infants and young children. In adults and older children, sputum induction has been successfully used; this technique has not been tested in younger children. AIMS: To investigate whether sputum induction can be successfully performed in infants and young children and to determine the utility of induced sputum compared to gastric lavage (GL) for the diagnosis of pulmonary tuberculosis in HIV infected and uninfected children. SUBJECTS AND METHODS: 149 children (median age 9 months) admitted to hospital with acute pneumonia who were known to be HIV infected, suspected to have HIV infection, or required intensive care unit support. Sputum induction was performed on enrollment. Early morning GL was performed after a minimum four hour fast. Induced sputum and stomach contents were stained for acid fast bacilli and cultured for Mycobacterium tuberculosis. RESULTS: Sputum induction was successfully performed in 142 of 149 children. M tuberculosis, cultured in 16 children, grew from induced sputum in 15. GL, performed in 142 children, was positive in nine; in eight of these M tuberculosis also grew from induced sputum. The difference between yields from induced sputum compared to GL was 4.3% (p = 0.08). M tuberculosis was cultured in 10 of 100 HIV infected children compared to six of 42 HIV uninfected children (p = 0.46). CONCLUSION: Sputum induction can be safely and effectively performed in infants and young children. Induced sputum provides a satisfactory and more convenient specimen for bacteriological confirmation of pulmonary tuberculosis in HIV infected and uninfected children. (+info)
Emergency management of poisoning in Hong Kong.
(6/88)
The emergency management of poisoning is important in reducing the risk of mortality and morbidity in poisoned patients. This article reviews the Hong Kong system of prehospital and emergency care of poisoning, with reference to recent advances in this field. Administering activated charcoal is recommended for the gastro-intestinal decontamination of most poisons, unless doing so is contra-indicated. Gastric lavage should be considered only in life-threatening cases of poisoning that present within the first hour. Newer antidotes that are available in Hong Kong accident and emergency departments include hydroxocobalamin, stonefish and snake antevenenes, digoxin-specific antibodies, esmolol hydrochloride, and octreotide. The 'golden hour' concept of gastro-intestinal decontamination is advocated and ways to ensure that decontamination is performed within the 'golden hour' are suggested. (+info)
Reduced GLP-1 and insulin responses and glucose intolerance after gastric glucose in GRP receptor-deleted mice.
(7/88)
By applying a newly developed ELISA technique for determining biologically active intact glucagon-like peptide [GLP-1, GLP-1-(7-36)amide] in mouse, plasma baseline GLP-1 in normal NMRI mice was found to be normally distributed (4.5 +/- 0.3 pmol/l; n = 72). In anesthetized mice, gastric glucose (50 or 150 mg) increased plasma GLP-1 levels two- to threefold (P < 0.01). The simultaneous increase in plasma insulin correlated to the 10-min GLP-1 levels (r = 0.36, P < 0.001; n = 12). C57BL/6J mice deleted of the gastrin-releasing peptide (GRP) receptor by genetic targeting had impaired glucose tolerance (P = 0.030) and reduced early (10 min) insulin response (P = 0.044) to gastric glucose compared with wild-type controls. Also, the GLP-1 response to gastric glucose was significantly lower in the GRP receptor-deleted mice than in the controls (P = 0.045). In conclusion, this study has shown that 1) plasma levels of intact GLP-1 increase dose dependently on gastric glucose challenge in correlation with increased insulin levels in mice, and 2) intact GRP receptors are required for normal GLP-1 and insulin responses and glucose tolerance after gastric glucose in mice. (+info)
The in vivo gut micronucleus test detects clastogens and aneugens given by gavage.
(8/88)
A general testing battery for pharmaceuticals includes a bacterial gene mutation assay, an in vitro chromosomal aberration or a gene mutation test on mammalian cells and an in vivo test for chromosome/genome mutations. The aim of this study was to determine whether the in vivo mouse gut micronucleus assay could be a more sensitive method to detect direct clastogens and/or aneugens given orally by gavage than the in vivo bone marrow micronucleus assay (which can also detect indirect genotoxins). Two laboratories collaborated in this project, one analysing bone marrow cells and the other analysing gut cells from the same animals. The reference substances tested in this study were colchicine (COL), carbendazim (CAR), tubulazole (TUB) and griseofulvin (GRI), all known aneugens, and 1,2-dimethylhydrazine (DMH), a colon carcinogen with clastogenic activity. For all substances tested, the in vivo gut micronucleus test was as sensitive as or more sensitive than the in vivo bone marrow micronucleus assay: COL and TUB induced micronuclei in both gut and bone marrow cells; DMH, CAR and GRI induced micronuclei only in gut cells. The results show that the micronucleus test on gut cells is able to detect clastogens and aneugens given orally by gavage, some of which were not detected by the bone marrow micronucleus test. (+info)