Mercury from chlor-alkali plants: measured concentrations in food product sugar

Mercury cell chlor-alkali products are used to produce thousands of other products including food ingredients such as citric acid, sodium benzoate, and high fructose corn syrup. High fructose corn syrup is used in food products to enhance shelf life. A pilot study was conducted to determine if high fructose corn syrup contains mercury, a toxic metal historically used as an anti-microbial. High fructose corn syrup samples were collected from three different manufacturers and analyzed for total mercury. The samples were found to contain levels of mercury ranging from below a detection limit of 0.005 to 0.570 micrograms mercury per gram of high fructose corn syrup. Average daily consumption of high fructose corn syrup is about 50 grams per person in the United States. With respect to total mercury exposure, it may be necessary to account for this source of mercury in the diet of children and sensitive populations.

Impact of community-based instruction on the development of adaptive behavior of secondary-level students with mental retardation

The impact of community-based instruction on the development of adaptive behavior in 34 high school students with moderate to profound mental retardation was examined. Results were: (a) Students made statistically significant gains in three of four domains of the Scales of Independent Behavior; (b) student IQ, level of student ambulation, and presence of behavior problems were not significant predictors of the amount of community-based instruction students received; and (c) the amount of community-based instruction was a more powerful predictor of gains in these domains than were IQ, level of student ambulation, and the presence of behavior problems. Results were discussed in terms of implications for the design and implementation of secondary programs for students with mental retardation.

Regulation of acid secretion by bombesin/GRP neurons of the gastric fundus

Intramural neurons in the fundus of the isolated mouse stomach were activated by 1,1-dimethyl-4-phenylpiperazinium (DMPP) or by electrical field stimulation and the participation of cholinergic and bombesin/gastrin-releasing peptide (GRP) neurons in the regulation of acid secretion evaluated with atropine and a selective bombesin/GRP antagonist, [Leu13-psi(CH2NH)-Leu14]bombesin. For both DMPP and field stimulation, atropine inhibited acid secretion and augmented somatostatin secretion. The bombesin/GRP antagonist had an opposite effect, augmenting acid secretion and inhibiting somatostatin secretion to below basal levels. The combination of the two antagonists restored DMPP- and field-stimulated acid and somatostatin secretion to basal levels. The results indicate that neurally stimulated acid secretion in the isolated mouse stomach is regulated by cholinergic neurons that mediate stimulation and bombesin/GRP neurons that mediate inhibition of acid secretion. Cholinergic neurons exert their stimulatory effect by acting directly on parietal cells and indirectly by eliminating the inhibitory influence of somatostatin. Bombesin/GRP neurons exert their inhibitory effect mainly by inducing release of somatostatin; an additional direct inhibitory effect of bombesin/GRP neurons on parietal cells is possible.

Functionally distinct muscarinic receptors on gastric somatostatin cells

The present study was designed to examine the mode of action of muscarinic agonists on somatostatin secretion in intact gastric tissues, i.e., mucosal segments from the fundus and antrum of rat and the isolated luminally perfused mouse stomach. Methacholine caused similar decreases in somatostatin secretion in segments from the fundus (35 +/- 3%; P less than 0.001) and antrum (35 +/- 2%; P less than 0.001) of rat stomach, and in whole mouse stomach (43 +/- 3%; P less than 0.001). The decrease was the net effect of a dominant inhibition and a lesser stimulation of somatostatin secretion. Pretreatment with the permeant derivative of the acetomethoxy ester form of the calcium chelator 1,2-bis(2-aminophenoxy)ethane-N,N,N',N'-tetraacetic acid (BAPTA/AM, 15 microM) caused a further decrease in methacholine-induced somatostatin secretion, implying that a stimulatory component existed that was mediated by intracellular calcium. Pretreatment with pertussis toxin (125 ng/ml) for 60 min converted the decrease in somatostatin secretion to an increase above basal levels. The increase induced by pretreatment with pertussis toxin was abolished by additional pretreatment with BAPTA/AM. Procaine (5 mM), which blocks release of calcium from intracellular stores, produced an effect on somatostatin secretion similar to that of BAPTA/AM. The results indicate that 1) methacholine exerts dual inhibitory and stimulatory effects on somatostatin cells of rat and mouse stomach, 2) the dominant effect is inhibitory and sensitive to pertussis toxin, and 3) a concurrent stimulatory effect, mediated by calcium, is unmasked after blockade of the inhibitory effect with pertussis toxin.

Employment preparation for high school students with severe handicaps

An ecological model for employment preparation in high schools that is based upon successful postschool community job placement for students with severe handicaps was discussed. The functions of employment training were analyzed, the components of a community-referenced model for high school training described, and implications drawn for model utility in relation to curriculum and instruction in high school programs.

Inhibition of acid secretion by bombesin is partly mediated by release of fundic somatostatin

The effect and mode of action of bombesin on gastric acid secretion was examined in the isolated, luminally perfused mouse stomach. Bombesin caused a concentration-dependent inhibition of basal and histamine-stimulated acid secretion and an increase in somatostatin secretion. Pertussis toxin was used to determine the contribution of somatostatin to the observed inhibition of acid secretion. Previous studies have shown that at a concentration of 125 ng/ml, pertussis toxin reverses completely the inhibition of acid secretion induced by exogenous and endogenous somatostatin. Preincubation of the stomach for 60 min with pertussis toxin (125 and 1250 ng/ml) reversed partially the inhibitory effect of bombesin on basal and histamine-stimulated acid secretion by 51%-59%, implying that bombesin-induced inhibition was partly mediated by release of somatostatin. The residual inhibition may represent a direct effect of bombesin on parietal cells.

Linkage between somatostatin and acid secretion: evidence from use of pertussis toxin

Pertussis toxin was used to examine the functional linkage between somatostatin and acid secretion and the mode of action of somatostatin at the cellular level in the isolated luminally perfused mouse stomach. Pretreatment of the stomach with pertussis toxin (125-1,250 ng/ml) for 60 min 1) caused a significant twofold increase in histamine-stimulated acid secretion (from 42 +/- 7 to 82 +/- 12 nmol/min; P less than 0.01) but not pentagastrin-stimulated secretion and 2) blocked the inhibitory effect of somatostatin on basal and histamine-stimulated acid secretion but not on pentagastrin-stimulated acid secretion. The ability of pertussis toxin to reverse selectively the inhibitory effect of somatostatin on histamine-stimulated acid secretion is consistent with the ability of pertussis toxin to inactivate a guanine nucleotide binding protein, which couples somatostatin receptors to inhibition of adenylate cyclase; histamine, but not gastrin, stimulates acid secretion via activation of adenylate cyclase. Secretagogue-stimulated acid secretion was accompanied by a parallel increase in somatostatin secretion that is largely determined by luminal acidity. The augmentation of histamine-stimulated acid secretion after treatment with pertussis toxin implied that the concomitant increase in somatostatin secretion is coupled to acid secretion and acts to attenuate it. The results confirm the role of gastric somatostatin as a paracrine regulator of acid secretion.